The doctor knows that people taking the medicine may sleep better just because they expect the medicine to work. How can he be sure of whether the medicine really works?

Answers

Answer 1

The best test would be doing a double-blind test between the person who is receiving the medicine so that they don't know if they received a placebo or not and the person giving the medicine does not know if the participant is receiving a placebo or not.

However, a placebo test can simply be done. This is where the patient received a medicine that does not have any medicinal effects and see if the person sleeps better. If they say they did, they have fallen under the placebo effect.


Related Questions

Which gas will diffusion faster within a system?

Carbon dioxide
Water vapor
Ammonia (NH3)
Methane(CH4)

Answers

Answer:

Methane(CH₄).

Explanation:

Thomas Graham found that, at a constant  temperature and pressure the rates of effusion  of various gases are inversely proportional to  the square root of their masses.

∨ ∝ 1/√M.

where, is the rate of diffusion of the gas.

M is the molar mass of the gas.

∨₁/∨₂ = √(M₂/M₁)

The molar mass of different choices:

Carbon dioxide: 44.01 g/mol.

Water vapor : 18.0 g/mol.

Ammonia (NH₃): 17.0 g/mol.

Methane(CH₄): 16.0 g.mol.

Since, methane has the lowest molar mass. So, it will diffuse faster within a system.

Calculate the approximate volume of a 1.50 mol sample of gas at 15.0oc and a pressure of 3.75 atm.

Answers

The approximate value of the volume of the gas is 958.3L

Ideal gas equation

Using the ideal gas equation which is a combination of pressure law, Boyle's law and Charles's law.

Mathematically

[tex]PV=nRT[/tex]

P = pressure = 3.75atmV = volume = unknownR = molar gas constant = 8.314J/mol.Kn = number of moles = 1.50molesT = 15°C

we convert the value of temperature from degree Celsius to Kelvin.

To do this, simply add 273.15 to the °C value.

[tex]T=15 + 273.15 = 288.15K[/tex]

From the data given, we can substitute into the equation and solve for v

[tex]PV = nRT\\3.75*V=1.5*8.314*288.15\\3.75V=3593.52\\V=\frac{3593.52}{3.75}\\V=958.27L[/tex]

The approximate value of the volume is 958.3L

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What to do if carbon monoxide alarm is going off

Answers

Go to the hospital. The Carbon Monoxide is poisonous and can cause death.
Exit the building/ premise immediately! Make sure all people/pets are out. Call fire department and go to hospital to get checked out

De Broglie developed the idea that matter in motion exhibits _______ properties.

Answers

DeBroglie developed the idea that matter in motion exhibits wavelike properties. These can be calculated based on the weight and velocity of objects.

Hope this helps!

According to the law of conservation of energy, the total amount of energy in the universe is Question 20 options: decreasing constant

Answers

According to the Law of Conservation of Energy, the total amount of energy in the universe remains constant. The total amount we have now is what we had at the time of the birth of the universe around 13.8 billion years ago, and it’ll be the same amount 10^100 years from now, too.

A gas has a volume of 750 mL at a pressure of 2.15 atm. What will the pressure be if the volume becomes 1.25 L?

Answers

Answer:

1.29 atm.

Explanation:

To calculate the volume of a gas, we can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

If n and T are constant, and have two different values of V and P:

P₁V₁ = P₂V₂

P1 = 2.15 atm, V1 = 750 mL = 0.75 L.

P₂ = ??? atm, V₂ = 1.25 L.

∴ P₂ = P₁V₁/V₂ = (2.15 atm)(0.75 L)/(1.25 L) = 1.29 atm.

The pressure will be [tex]\( 1.29 \, \text{atm} \)[/tex] when the volume becomes [tex]\( 1.25 \, \text{L} \)[/tex].

To solve this problem, we can use Boyle's Law, which states that the pressure of a gas is inversely proportional to its volume when the temperature and amount of gas are held constant. Mathematically, Boyle's Law is represented as: [tex]P_1 \times V_1 = P_2 \times V_2 \][/tex]

Where:

[tex]\( P_1[/tex] is the initial pressure

[tex]\( V_1 \)[/tex] is the initial volume

[tex]\( P_2 \)[/tex] is the final pressure

[tex]\( V_2 \)[/tex] is the final volume

Given:

[tex]\( P_1 = 2.15 \) atm[/tex]

[tex]\( V_1 = 750 \) mL = \( 0.750 \) L[/tex]

[tex]\( V_2 = 1.25 \) L[/tex]

We can rearrange Boyle's Law to solve for [tex]\( P_2 \)[/tex]:

[tex]\[ P_2 = \frac{P_1 \times V_1}{V_2} \][/tex]

Substitute the given values:

[tex]\[ P_2 = \frac{2.15 \, \text{atm} \times 0.750 \, \text{L}}{1.25 \, \text{L}} \][/tex]

[tex]\[ P_2 = \frac{1.6125 \, \text{atm} \cdot \text{L}}{1.25 \, \text{L}} \][/tex]

[tex]\[ P_2 = 1.29 \, \text{atm} \][/tex]

Which has more surface area, a rock the size of your hand or a handful of small rocks?

Answers

The handful of small rocks

A handful of small rocks, there is more surface area because where there would normally be solid rock is surface area.

A pumpkin is dropped, after 5 secs, its velocity is 47m/s. What is its acceleration?

Answers

Given, final veocity = 47m/s, initial velocity= 0, time = 5s

V = u+at

a = v-u/t

   = 47- 0/5

   = 9.4 ms^-2

Why are the elements, carbon, hydrogen, oxygen, and nitrogen important to life on earth

Answers

because humans/animals/ plants etc. need living organisms to live.

Carbon, hydrogen, oxygen, and nitrogen are the primary "organic" elements because they are the building blocks that allow life to exist.

What is lifeform?

A living entity, such as plants and animals, is referred to as a life form (fauna). More than 99% of all species that have ever existed on Earth, totaling over five billion species, are thought to be extinct.

Humanity, as the highest form of life, bears a clear responsibility in locating this path.

Inventory of the Universe delves into the mechanics of human life, including genes, DNA, stem cells, reproduction, chronobiology, and many other aspects of human composition.

Carbon, hydrogen, oxygen, and nitrogen are the chief elements because they are the foundational blocks that allow life to exist.

Carbon is the most unique of the four because it can form bonds with itself and create molecules in a variety of shapes.

Thus, these elements are mandatory for life.

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The characteristic reaction for unsaturated hydrocarbons is substitution.

True or False

Answers

Answer;

The statement above is False;

Explanation;Saturated hydrocarbons also known as alkanes contain only a single covalent bonds between carbon atoms. The common feature found in all saturated hydrocarbons is carbon-carbon multiple bonds. Unsaturated hydrocarbons are hydrocarbons in which all the valencies of carbon atoms are not fully utilized by single covalent bonds. They contain at least one double or triple bond in their structure.Characteristic reactions of alkanes or saturated hydrocarbons are substitution reactions. Unsaturated hydrocarbons characteristics reactions are addition reactions.

A charge of 5.0 coulombs moves through a circuit in 0.50 second. What is the current in the circuit?

Answers

Answer:

10.0 A.

Explanation:

∵ Q = It.

where, Q is the no. of coulombs.

I is the current in A.

t is the time in s.

∴ I = Q/t = (5.0 C)/(0.50 s) = 10.0 A.

If a reaction is exothermic and its entropy change is positive, which statement is true? If a reaction is exothermic and its entropy change is positive, which statement is true? a. The reaction is spontaneous only at higher temperatures. b. The reaction is nonspontaneous at all temperatures. c. The reaction is spontaneous at all temperatures. d. The reaction is spontaneous only at lower temperatures.

Answers

Answer:

c. The reaction is spontaneous at all temperatures.

Explanation:

The spontaneity of a reaction can be determined by the thermodynamic property named Gibb's free energy or simply free energy (G).

The change in the free energy of a system is defined as the difference between the increase in enthalpy (ΔH) and the product of the temperature (T) times the increase in entropy (ΔS):

ΔG = ΔH - T ΔS

The sign of ΔG tells if a reaction is spontaneous according to this:

ΔG < 0, the reaction is spontaneous. ΔG = 0, the reaction is in equilibrium. ΔG > 0, the reaction is not spontaneous.

The question states that a reaction is exothermic, and its entropy change is positive. That means:

Exhotermic: ΔH < 0Positive entropy change: ΔS > 0

Remember that the temperature is stated in absolute scale, so T is always positive.

Hence, ΔG = ΔH - T ΔS = (negative) - T (positive) = (negative) + (negative) = negative.

Conclusion: since ΔG is negative, regardless the temperature, you conclude that the reaction is spontaneous at all temperatures, which is the option c.

The answer is C. This reaction is spontaneous at all temperatures.

Further Explanation

Heat is an energy that is easily received and easily released so that it can change the temperature of these substances into rising or falling. Heat can also move from one substance to another through a medium or intermediary. For example, two substances that have different temperatures are mixed in a container. Then the temperature of the two objects will be the same.

An endothermic reaction is a reaction that absorbs heat (there is heat transfer from the environment to the system). Endothermic reaction (endo-is a prefix meaning "inward"), where heat must be supplied to the system by the environment. In this reaction, there is heat transfer from the environment to the system so that the ambient temperature drops and becomes colder. Endothermic reactions absorb a certain amount of energy so that the energy of the system increases. Because enthalpy increases, the enthalpy change is positive. In endothermic reactions, the system absorbs energy. Therefore, the enthalpy of the system will increase. That is, the product enthalpy (Hp) is greater than the reactant enthalpy (Hr). As a result, the enthalpy change is the difference between the product enthalpy and the reactant enthalpy (Hp-Hr) which is positive. And the enthalpy changes for endothermic reactions can be stated as follows:

∆H = Hp-Hr> 0 (Positive)

Exothermic reactions are chemical reactions that produce heat. In this reaction, there is heat transfer from the system to the environment so that the environment becomes hotter. The exothermic reaction sign is a negative enthalpy change (∆H = -). This is because the exothermic reaction will release energy so that the enthalpy of the system decreases. Examples of exothermic reactions include combustion reactions, such as wood combustion, methane, propane, and the reaction between aluminum powder and iron oxide. Another example of an exothermic reaction in the manufacture of ethanol from glucose fermentation.

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Grade: High School

Subject: Chemistry

keywords: Exothermic reactions, Heat

Which of the following substances is a weak base?
a. NaOH
b. NH3
c. K2O
d. KOH

Answers

Answer:

b. NH₃.

Explanation:

Firstly, we need to defined the base;

Base is the substance that can produce OH⁻ ions in the solution.

So, NaOH, KOH, and NH₃ are bases because they can produce OH⁻ ions in the solution.

But, K₂O is not a base, it can not produce OH⁻ ions in the solution.

Now, we need to differentiate between strong and weak bases.

Strong bases are bases that can completely ionized in the solution and produce OH⁻ ions.

NaOH and KOH are strong bases because they can completely ionized in the solution and produce OH⁻ ions.

Weak bases are bases that can not completely ionized (ionized partially) in the solution and produce OH⁻ ions.

NH₃is a weak base hat can not completely ionized (ionized partially) in the solution and produce OH⁻ ions.

So, the right choice is: NH₃.

The substance listed as a weak base is NH₃ (ammonia), which does not dissociate completely in solution, distinguishing it from strong bases like NaOH and KOH. Option b is correct.

The substance listed that is classified as a weak base is NH₃, also known as ammonia. A characteristic of weak bases is that they do not dissociate completely in solution. For example, in a 1 M solution of ammonia, only a small percentage (~0.42%) of the dissolved NH₃ molecules dissociate into ammonium ions and hydroxide ions (OH-) in water. This is in contrast to strong bases like NaOH and KOH, which dissociate almost completely in water, releasing a large number of hydroxide ions and making the solution highly alkaline.

Therefore, the correct answer to the student's question is NH₃ Substances like NaOH and KOH, which were also listed, are classified as strong bases due to their complete dissociation in solution, which is provided by their metal and -OH group.

How many moles of water are produced when 24.3 ml of 0.100 m naoh is mixed with 31.4 ml of 0.08 m acetic acid?

Answers

Answer;

0.002512 moles of H2O

Explanation;

The reaction between acetic acid ( CH3COOH) and NaOH is given by the equation;

CH3COOH + NaOH ------> CH3COONa + H2O

Number of moles of CH3COOH = molarity × volume in litres

                                                     = 0.08 × 31.4/1000

                                                     = 2.512 × 10^-3  

Similarly number of moles of NaOH = 1 × 24.3/1000

                                                      = 0.0243

From the reaction the mole ratio of CH3COOH : NaOH

Therefore; 0.0243 moles of NaOH will react with 0.0243 moles of CH3COOH but no.of moles of CH3COOH given in the question are 0.002512  moles, which is less than what is required.

Thus; CH3COOH is the limiting reagent and amount of products produced will depend on amount of CH3COOH only.

Since; 1 mole of CH3COOH gives 1 mole of water.

Then; 0.002512 moles of CH3COOH will give 0.002512 moles of H2O

The number of moles produced from the reaction of 24.3 mL of 0.100 M NaOH with 31.4 mL of 0.08M acetic acid is 2.43x10⁻³ moles.

The acid-base reaction between NaOH and CH₃COOH is the following:

NaOH + CH₃COOH ⇄ H₂O + CH₃COONa

To find the number of moles of water produced we need to calculate the number of moles of NaOH and CH₃COOH

[tex] n = C*V [/tex]

Where:  

n: is the number of moles

C: is the concentration

V: is the volume

So, the number of moles of NaOH and CH₃COOH is:

[tex] n_{NaOH_{i}} = C_{NaOH}*V_{NaOH} = 0.100 M*0.0243 L = 2.43 \cdot 10^{-3} moles [/tex]

[tex] n_{{CH_{3}COOH}_{i}} = C_{CH_{3}COOH}*V_{CH_{3}COOH} = 0.08 M*0.0314 L = 2.51 \cdot 10^{-3} moles [/tex]

Now, we need to find the limiting reactant knowing that 1 mol of NaOH reacts with 1 mol of CH₃COOH:

[tex] n_{NaOH} = \frac{1\: mol NaOH}{1\: mol CH_{3}COOH}*2.51 \cdot 10^{-3} \: moles\: CH_{3}COOH = 2.51 \cdot 10^{-3} \: moles [/tex]

We can see that we need 2.51x10⁻³ moles of NaOH to react with CH₃COOH, and initially, we have 2.43x10⁻³ moles of NaOH, so the limiting reactant is NaOH.  

Knowing that 1 mol of NaOH reacts with 1 mol of CH₃COOH to produce 1 mol of H₂O and 1 mol of CH₃COONa, the number of moles of water produced is:

[tex] n_{H_{2}O} = n_{NaOH} = 2.43 \cdot 10^{-3} moles [/tex]

Therefore, the number of moles of water produced is 2.43x10⁻³ moles.

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In a 0.738 m solution, a weak acid is 12.5% dissociated. calculate ka of the acid.

Answers

Final answer:

To find the Ka of a weakly dissociated acid, use the degree of dissociation to calculate the concentrations of the ions and the remaining acid. Put these into the Ka expression and solve.

Explanation:

In a 0.738 m solution, a weak acid is 12.5% dissociated and we're looking to calculate the Ka of the acid. For a weak acid dissociation, we consider the acid ionization equilibrium

HA ⇌ H+ + A-

The degree of ionization is given and we can use it to calculate the concentration of the ions. Since the acid is 12.5% dissociated, the concentration of H+ and A- is 0.125 x 0.738 mol/L.

The Ka is the equilibrium constant for the dissociation reaction of the acid. It is given by:

Ka = [H+][A-]/[HA]

where [HA] is the concentration of the undissociated acid. Because only 12.5% of the acid is dissociated, [HA] remaining is 0.875 x 0.738 mol/L. So,

Ka = (0.125 x 0.738)² / (0.875 x 0.738)

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Final answer:

The dissociation constant (Ka) of a weak acid in a solution can be calculated by substituting the molarity of the solution and the percentage of dissociation into the formula of Ka. For a 0.738 M solution where the weak acid is 12.5% dissociated, the Ka is calculated as 0.016*0.738.

Explanation:

In your 0.738 M solution, the weak acid is 12.5% dissociated. Given that the percent dissociation is 12.5%, we can infer that if the initial concentration of the acid is represented by 'C', the degree of dissociation (α) = [H₃O⁺]eq / C = 0.125. Therefore, the concentration of H₃O⁺ (or A⁻) and HA at equilibrium can be represented as 0.125C and 0.875C, respectively.

The expression for the dissociation constant for the weak acid, HA → H⁺ + A⁻ would be,

Ka = [H⁺][A⁻]/[HA] = (0.125C*0.125C)/0.875C = 0.016C.

Since we know the molarity of the solution (0.738), we can substitute it into the equation Ka=0.016*0.738, to get the value of Ka which will represent the acid dissociation constant for this weak acid.

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A central atom that is sp3 hybridized could bind up to how many other atoms?

Answers

Answer: up to 4 other atoms.

Explanation:

Hybridization sp³ means that the atom has 4 equal orbitals formed by the combination of 1 s and 3 p orbitals.

Each of these sp³ orbitals is a place for a chemical bonding.

Hence, since each orbital is able to bind a different atom, you conclude that a central atom that is sp³ hydridized could bind up to 4 other atoms.

This is precisely the case for carbon (C) atoms.

Carbon has atomic number 6. So its electron configuration is 1s² 2s²p².

The four electrons in the level 2, those shown in 2s² 2p², are in two different orbitals: two are in the orbital 2s and two are in the orbitals 2p.

This diagram shows how those 4 electrons fill the orbitals

2s⇅ 2px↑ 2py↑

The two 2s electrons have lower energy level than the 2px and 2 py electrons, but the difference is not too big.That is why one of the electrons in the 2s ortital can be promoted to the empty 2pz orbital, and you get 4 equal hydridized ortibals, so called sp³.

And that is why, carbon (C) ends up with 4 equal (hydridized) orbitals which can bind up to 4 different atoms, including other carbon atoms, and so, form long chains and, virtually, infinite compounds.

Final answer:

A sp³ hybridized central atom could bind up to four other atoms, due to the four sp³ hybrid orbitals formed from the hybridization process.

Explanation:

The central atom in a molecule that is sp³ hybridized is surrounded by a tetrahedral arrangement of bonding pairs and lone pairs, consisting of a set of four sp³ hybrid orbitals. This hybridization results from the mixing of one s orbital and all three p orbitals, generating four identical sp³ hybrid orbitals, each pointing towards a difference corner of a tetrahedron. This means that a sp3 hybridized central atom could bind up to four other atoms.

For instance, the carbon atoms in a methane molecule (CH₄) are sp³ hybridized, and each carbon atom is connected to four hydrogen atoms. Also, the nitrogen atom in ammonia (NH₃) is sp³ hybridized, binding to three hydrogen atoms and also holding a lone pair of electrons in the fourth sp3 hybrid orbital.

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Determine the velocity of a marble (m = 8.66 g) with a wavelength of 3.46 × 10-33m.a.45.2 m/sb.11.3 m/sc.22.1 m/sd.38.8 m/se.52.9 m/s

Answers

Final answer:

The velocity of the marble can be determined using the de Broglie equation which relates a particle's wavelength to its momentum. Given the marble's mass and wavelength, plug these values into the de Broglie equation and solve for the velocity.

Explanation:

To determine the velocity of the marble, we can use the de Broglie equation, which relates the wavelength of a particle to its momentum. This equation is λ = h/mv, where λ is the wavelength, h is Planck's constant (6.626 x 10^-34 m^2 kg / s), m is the mass of the particle, and v is the speed (velocity) of the particle.

In this problem, we are given: the mass (m) of the marble as 8.66 g (which we convert to kg by dividing by 1000 to get 0.00866 kg), the wavelength (λ) of the marble is given as 3.46 x 10^-33 m, and we are asked to solve for velocity (v). Inserting these numbers into the de Broglie equation, we get: v = h/(mλ) = (6.626 x 10^-34 m^2 kg / s) / (0.00866 kg x 3.46 x 10^-33 m) (solve this on your calculator to get the answer). Due to the given options, the calculated answer must be one of them.

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Select the properties of the Sn2 reaction mechanism. a. stereospecific: 100% inversion of configuration at the reaction site b. not stereospecific c. bimolecular at rate-determining step d. unimolecular at rate-determining step e. first order second order rate is governed by steric effects f.rate is governed by the stability of the carbocation that is formed

Answers

The properties of the SN2 (substitution nucleophilic bimolecular) reaction mechanism are stereospecific, bimolecular at the rate-determining step and first order. Therefore, options A, C, and E are correct.

a. Stereospecific: 100% inversion of configuration at the reaction site. This means that the configuration of the stereo center undergoes an inversion during the reaction.

c. Bimolecular at the rate-determining step. The Sn2 reaction involves the simultaneous interaction of two molecules: the nucleophile and the substrate.

e. First order: The rate of the SN2 reaction is first order with respect to both the nucleophile and the substrate.

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Which sentences describe alpha particles? Check all that apply 1. Alpha particles consist of two protons and two neutrons 2. Alpha particles consist of a negatively charged electron emitted by a nucleus 3. Alpha particles are produced during alpha decay 4. Alpha particles are produced during beta decay 5. Alpha particles release energy.

answers: 1,3,5 on ed-genuity ...good luck!!

Answers

thanks for the answers ッ. (btw they’re on the bottom of the question if anyone doesn’t see it.

Alpha particles consist of two protons and two neutrons, it is produced during alpha decay and release energy.

What is alpha particles?

Alpha particles are the small part of a matter which carry positive charge in it.

From the definition of the alpha particles, it is clear that it is positively charged particle and no electron is present in it. It mainly consist 2 protons and 2 neutrons in it. It is produced by the decay of very heavy radioactive elements which are unstable and releases energy with alpha particle to gain stability, and this decay is known as alpha - decay.

Hence, option (1), (3) and (5) is correct.

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A certain indicator, ha, has a ka value of 1.0Ã10â6. the protonated form of the indicator is blue and the ionized form is yellow. what is the pka of the indicator?

Answers

Final answer:

The pKa of the indicator in this scenario is 6. The color of the solution will be yellow when the pH > 6 and blue when the pH < 6. At pH = 6, the solution will display a mixture of both colors.

Explanation:

The pKa of an indicator is the negative logarithm (base 10) of the Ka value. In this case, given the Ka value of 1.0Ã10â6, the pKa is -log(1.0Ã10â6), which equals 6. The colors the indicator presents depend on the pH of the solution. When the pH is greater than pKa, the solution tends to have the color of the conjugate base, which in this case is yellow. Conversely, when the pH is less than pKa, the solution takes on the color of the protonated form (the acid form), which in this case is blue. At a pH equal to the pka, you would see a mixed color, as appreciable amounts of both the conjugate acid and base are present. This information can be applied when considering the use of indicators in a titration scenario or when attempting to determine the approximate pH of an unknown solution.

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Final answer:

The pKa of the indicator ha with a ka value of 1.0x10^(-6) is 6.

Explanation:

The pKa of an indicator can be calculated using the Henderson-Hasselbalch equation, which relates the ratio of the concentrations of the conjugate base and conjugate acid forms of the indicator to the pH of the solution:



pKa = -log (ka)



For the given indicator, ha, with a ka value of 1.0x10^(-6), the pKa can be calculated as follows:



pKa = -log (1.0x10^(-6)) = 6



Therefore, the pKa of the indicator ha is 6.

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When 6.0 mol Al react with 13 mol HCl, what is the limiting reactant, and how many moles of H2 can be formed?
2Al + 6HCl → 2AlCl3 + 3H2
a. Al is the limiting reactant, and 9.0 mol H2 can be formed
b. HCl is the limiting reactant, and 6.5 mol H2 can be formed
c. Al is the limiting reactant, and 6.0 mol H2 can be formed
d. HCl is the limiting reactant, and 4.3 mol H2 can be formed

Answers

You're looking for the number of moles of H2, and you have 6.0 mol Al and 13 mol HCL.

For the first part, you have to make your way from 6.0 mol of Al to mol of H2, right? For that to happen, you need to make a conversion factor that will cancel the mol Al, in such case use the 2 moles of Al from your equation to cancel them out. At the top of the equation, you can use the number of moles of H2 from the equation and find the moles that will be produced for the H2.

6.0mol Al x 3 mol H2/2 mol Al = 9 mol H2

For the second part, you have to make the same procedure, make a conversion factor that will cancel the mol of HCL and for that you need to use the 6 mol HCL from your equation, and at the numerator you can put the 3 mol of H2 from the equation so that you can find the number of moles of H2 that will be produced.

13 mol HCL x 3 mol H2/6 mol HCL = 6.5 mol H2

As it can be seen, HCL produces the less amount of H2 moles. Therefore, the reaction CANNOT produce more than 6.5 mol H2, in that case 6.5 mol will be the maximum number of moles that will be produced at the end because HCL does not have enough to produce more than 6.5 mol.

In that case HCL is the limiting reactant because it limits that will be produced, and so the answer is B!

Complete this equation to show how pyridine, C5H5N, acts as a Brønsted-Lowry base in water.C5H5N+H2O--->

Answers

Answer:

C5H5H + H2O → C5H5NH+ + OH-

Explanation:

C5H5H + H2O → C5H5NH+ + OH-  

C5H5N + H+ → C5H5NH+  

C5H5N - Proton acceptor

A Bronsted-Lowry base is a solution that acts as a proton or hydrogen ion acceptor.A Bronsted-Lowry acid on the other hand, is a solution that acts as a proton or hydrogen ion donor.In our case; C5H5N is the Proton acceptor while H2O is the proton Donor.

Answer : The complete equation will be,

[tex]C_5H_5N+H_2O\rightleftharpoons C_5H_5NH^++OH^-[/tex]

Explanation :

According to the Bronsted Lowry concept, Bronsted Lowry-acid is a substance that donates one or more hydrogen ion in a reaction and Bronsted Lowry-base is a substance that accepts one or more hydrogen ion in a reaction.

The given reaction will be,

[tex]C_5H_5N+H_2O\rightleftharpoons C_5H_5NH^++OH^-[/tex]

In this reaction, [tex]C_5H_5NH^+[/tex] is act as a Bronsted Lowry-base by accepting one hydrogen ion from the water and [tex]OH^-[/tex] is act as a Bronsted Lowry-acid by donating one hydrogen ion to pyridine.

The experimental procedure has you wash your thermometer and dry it after you measure the temperature of the acid and base solutions. how would your result be affected if you measure the temourature of th hcl solution and immediately ,easure the tempurature of the naoh solution without rinsing and drying the thermometer?

Answers

If you don't wash the thermometer, residual NaOH will react with the HCl solution. This is a highly exothermic reaction and will change the temperature of the solution, and thus throw off your measurement.

Final answer:

Not rinsing and drying the thermometer between measurements in an experiment involving HCl and NaOH solutions could skew results by unintentionally introducing acid or base into the other solution, altering the pH and temperature readings, and potentially the titration results.

Explanation:

In the experimental procedure where you measure the temperature of an HCl solution and then a NaOH solution without rinsing and drying the thermometer, your results may be compromised. This is because there could be a carry-over of acid (HCl) or base (NaOH) from one solution to the other which could potentially affect the pH of the solutions being measured. The pH of a solution is dependent on its hydrogen ion concentration, so any residual acid or base on the thermometer could interact with the other solution, altering its pH and therefore its temperature.

Titration is a technique that uses a solution of known concentration to find the concentration of an unknown solution. In your experiment, if you measured the temperature of the HCl solution and then immediately measured the temperature of the NaOH solution without rinsing and drying the thermometer, you might unintentionally introduce some HCl into the NaOH solution. This could potentially skew your results as the introduction of acid could decrease the pH of the NaOH solution, making it less basic than it actually is, and this could affect the titration results.

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The average rate of disappearance of ozone in the reaction 2o3(g) → 3o2(g) is found to be 7.25×10–3 atm over a certain interval of time. what is the rate of appearance of o2 during this interval?

Answers

Answer;

1.0875 x 10-2 atm

Explanation;

2O3(g) → 3O2(g)

rate = -(1/2)∆[O3]/∆t = +(1/3)∆[O2)/∆t  

The average rate of disappearance of ozone ... is found to  

be 7.25 × 10–3 atm over a certain interval of time.

This means (ignoring time)

∆[O3]/∆t = -7.25 × 10^–3 atm  

(it is disappearing, thus the negative sign)

rate = -(1/2)∆[O3]/∆t  

rate = -(1/2)*(-7.25 × 10^–3 atm)

      = 3.625 × 10^–3 atm  

Now use the other part of the expression:  

rate = +(1/3)∆[O2)∆t  

3.625 × 10–3 atm = +(1/3)∆[O2)/t  

∆[O2)/∆t = (3)*(3.625× 10^–3 atm)

              = 1.0875 x 10-2 atm over the same time interval

From the parameters given, the rate of appearance of O2 is 1.1 * 10^-2.

The equation of the reaction is;

2O3(g) → 3O2(g)

We can see from the equation that; [tex]-\frac{1}{2} \frac{d[O3]}{dt} = \frac{1}{3} \frac{d[O2]}{dt}[/tex]

Hence it follows that;

[tex]-\frac{3}{2} \frac{d[O3]}{dt} = \frac{d[O2]}{dt}[/tex]

Since we already have the rate of disappearance of O3 from the problem as 7.25 × 10^-3, the rate of appearance of O2 is now given by;

[tex]\frac{d[O2]}{dt} = \frac{3}{2} * 7.25 * 10^-3[/tex]

[tex]\frac{d[O2]}{dt} = 1.1 * 10^-2[/tex]

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Remember to explain and show work.

26. How much heat will be absorbed if 45.0 g of C react with excess water?

27. How much heat is released when 9.22 grams of glucose C6H12O6 in your body reacts with according to the following equation?​

Answers

Answer:

26. 42.3 kJ; 27. 143 kJ  

Explanation:

26. Formation of water gas

We know that we will need the balanced equation with masses, molar masses, and enthalpies, so let’s gather all the information in one place.

A_r:        12.01

                 C + H₂O ⟶ CO + H₂; ΔH_r = +113 kJ

Mass/g:  4.50

(a) Calculate the moles of C

Moles of C = 4.50 × 1/12.01 = 0.375 mol C

(b) Calculate the energy absorbed

The conversion factor is 113 kJ/1 mol Al

Heat = 0.375 × 113/1 = 42.3 kJ

27. Oxidation of glucose

A_r:         180.16

               C₆H₁₂O₆ + 6O₂ ⟶ 6CO₂ + 6H₂O; ΔH_r =  -2803 kJ

Mass/g:     9.22

(a) Calculate the moles of C₆H₁₂O₆

Moles of C₆H₁₂O₆ = 9.22 × 1/180.16 = 0.051 07 mol C₆H₁₂O₆

(b) Calculate the energy absorbed

The conversion factor is (-2803 kJ/1 mol C₆H₁₂O₆)

Heat = 0.051 07 × (-2803)/1 = -143 kJ

The oxidation of glucose releases 143 kJ .

Is O2 always a double bond?

In the question about Bond Enthalpy it is 2H2O2 → 2H2O + O2

In the answers O-O is a double bond. How do I find out if something has a double bond without looking at the answers?

Answers

O-O single bonds and H-O single bonds in [tex]\text{H}_2\text{O}_2[/tex] molecules.H-O single bonds in [tex]\text{H}_2\text{O}[/tex] molecules.O=O double bonds in [tex]\text{O}_2[/tex] molecules.Explanation

How many valence electrons do atoms in each molecule need for them to be stable?

Each H atom needs two valence electrons to be stable. Each atom of an element other than H needs eight valence electron to be stable.There are two H atoms and two O atoms in an  [tex]\text{H}_2\text{O}_2[/tex] molecule. Atoms in each [tex]\text{H}_2\text{O}_2[/tex] need [tex]2 \times 1 + 2\times 2 = 6[/tex] more electrons to be stable.There are two H atoms and one O atom in an [tex]\text{H}_2\text{O}[/tex] molecule. Atoms in each [tex]\text{H}_2\text{O}[/tex] molecule need [tex]2 \times 1 + 2= 4[/tex] more electrons to be stable.There are two O atoms in an [tex]\text{O}_2[/tex] molecule. Atoms in each [tex]\text{O}_2[/tex] molecule need [tex]2 \times 2 = 4[/tex] more electrons to be stable.

How many chemical bonds in each molecule?

Each chemical bond adds one valence electron to each bonding atom. Each chemical bond connects two atoms. As a result, each chemical bond adds two valence electrons to the molecule.

Each [tex]\text{H}_2\text{O}_2[/tex] molecule needs [tex]6 / 2 = 3[/tex] chemical bonds.Each [tex]\text{H}_2\text{O}[/tex] molecule needs [tex]4 / 2 = 2[/tex] chemical bonds.Each [tex]\text{O}_2[/tex] molecule needs [tex]4 /2= 2[/tex] chemical bonds.

What chemical bonds are these? Again, each H atom needs only one more valence electron to be stable. It will share only one electron with O and form one H-O bond. The rest of the chemical bonds are between O atoms.

There are two H atoms in each [tex]\text{H}_2\text{O}_2[/tex] molecule, which form two H-O bonds. Two of the three chemical bonds in this molecule are H-O. The other is an O-O single bond between the two O atoms.There are two H atoms in each [tex]\text{H}_2\text{O}[/tex] molecule, which form two H-O bonds. Both chemical bonds in this molecule are H-O. There's no O-O bond in this molecule.There is no H atom in [tex]\text{O}_2[/tex] molecules. Both chemical bonds are between O atoms. However, there are only two O atoms. There must be two chemical bonds between the two O atoms. That bond will be an O-O double bond.

BRINCLHOF

Br

I

N

Cl

H

O

F

all have dounle bonds.

You could also do lewis structures for each molecule to figure out the structure.

How is sound energy produced? A. by vibrating objects B. by stationary objects C. by temperature differences D. by objects being heated

Answers

Sound energy is produced by vibrating objects.

Example: when you speak you vibrate the air molecules in the air. If you where to speak in space no “sound” would be produced since there is nothing for the vibration of your voice to travel through.

Answer:

A. vibrating objects

Explanation:

What type of flower is this? This is for a science project.

Answers

I believe it’s called Wisteria

A compound that conducts an electric current in aqueous solution or in the molten state.

Answers

Final answer:

An electrolyte is a compound that conducts an electric current in an aqueous solution or in the molten state. This happens when the substance dissolves in water and forms ions. The dissolved or molten ions can move freely, allowing the solution to conduct electricity.

Explanation:

A compound that conducts an electric current in an aqueous solution or in the molten state is known as an electrolyte. Electrolytes are formed when certain substances dissolve in water and either undergo a physical or a chemical change that yields ions in solution. These substances are important as they conduct electric current in a solution due to the presence of ions.

For example, ionic compounds like NaCl (table salt) disassociate completely in water forming Na+ and Cl- ions, giving the solution the ability to conduct electricity. In another example, covalent compounds like HCl (hydrochloric acid) also conduct electricity in water. This happens because when HCl is dissolved in water, it reacts with water molecules to form ions of H+ and Cl-.

However, the ability to conduct electricity is not limited to aqueous solutions; compounds can also conduct electricity in the molten state. For instance, when table salt is melted, it’s able to conduct electric current because the ionic bonds are broken, freeing the ions and enabling them to move and carry the current.

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What is the net ionic equation of the reaction of fecl2 with naoh?

Answers

Final answer:

In the reaction between FeCl₂ and NaOH, Fe²⁺ reacts with OH⁻ to form Fe(OH)₂(s) which precipitates out of the solution. The net ionic equation is: Fe²⁺(aq) + 2OH⁻(aq) -> Fe(OH)₂(s).

Explanation:

The reaction of FeCl₂ with NaOH is a chemistry problem asking for the net ionic equation. Firstly, we look at the molecular equation: FeCl₂(aq) + 2NaOH(aq) -> Fe(OH)₂(s) + 2NaCl(aq). Secondly, we determine the full ionic equation: Fe²⁺(aq) + 2Cl⁻(aq) + 2Na+(aq) + 2OH⁻(aq) -> Fe(OH)₂(s) + 2Na⁺(aq) + 2Cl-(aq). Finally, after eliminating the spectator ions, the net ionic equation is:

Fe²⁺(aq) + 2OH⁻(aq) -> Fe(OH)₂(s)

In this equation, Fe2+ reacts with OH- to form Fe(OH)₂ which precipitates out of the solution.

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