Need asap! 25 pts! Magnetic iron oxide has 72.4% iron and 27.6% oxygen. What is the empirical formula?​

Answers

Answer 1

Hi!

1. Assume that these percentages are the mass.

2. For each of Fe and O, divide the mass by the Ar (relative atomic mass).

Fe: 72.4/55.8 = 1.297 moles

O: 27.6/16 = 1.725 moles

3. Work out which mole value is smallest, then divide the bigger mole value by the smaller one.

1.297 is smaller than 1.725, so your empirical formula is 1.1297/1.1297 = 1 atom of iron, and 1.725/1.297 = 1.33 atoms of oxygen.

4. Ensure your atom values are whole numbers.

1.33 is not a whole number, so multiply both 1 and 1.33 by 3.

5. Write out your empirical formula.

Fe3O4

Hope that helps!

Answer 2
Final answer:

The empirical formula for magnetic iron oxide, given that it has 72.4% iron and 27.6% oxygen by mass, is Fe3O4.

Explanation:

The problem asks us to find the empirical formula for magnetic iron oxide. Given the percentage composition of iron and oxygen in the compound, we can look at it as if we had 100g of the substance. This would give us 72.4g of iron (Fe) and 27.6g of oxygen (O).

First, we convert these amounts to moles. The atomic mass of iron is approximately 55.845 g/mol and for oxygen is approximately 16.00 g/mol. Therefore, we have 1.3 mol Fe and 1.72 mol O.

To find the empirical formula, we divide each of these by the smallest number of moles to get a ratio. So, we have Fe1O1.3. However, an empirical formula should consist of whole numbers. Therefore, if we multiply both by the same factor, in this case, a factor of 3 will give us whole numbers, we get Fe3O4. Therefore, the empirical formula for magnetic iron oxide is Fe3O4.

Learn more about Empirical Formula here:

https://brainly.com/question/32125056

#SPJ3


Related Questions

Draw the structural formula for all the alkenes with the indicated molecular formula that, without undergoing a rearrangement, produce the compound shown as a major product g

Answers

ya got to go get sum to eat then get it

Which element has characteristics most similar to fluorine (F)? A. lead (Pb) B. hydrogen (H) C. nitrogen (N) D. bromine (Br)

Answers

bromine because they are both in Group 17, which means they have the same number of valence electrons

Answer:

Bromine (Br)

Explanation:

At constant temperature and pressure, 2.05 g of oxygen gas O2 is added to a 1.0 L balloon containing 1.00 g of O2. What is the new volume of the balloon?

Answers

Answer:

1.50 L.

Explanation:

From the general gas law:

PV = nRT,

Where, P is the pressure if the gas,

V is the volume if the gas container,

n is the no. of gas moles,

R is the general gas constant,

T is the temperature of the gas.

At constant P and T:

n₁V₂ = n₂V₁.

V₁ = 1.0 L, V₂ = ??? L.

n₁ = mass/molar mass = (2.05 g)/(32.0 g/mol) = 0.064 mol.

n₂ is the no. of moles of the total gas (2.05 g + 1.0 g).

n₂ = n₁ + (1.00 g)/(32.0 g/mol) = 0.0953 mol.

∴ V₂ = n₂V₁/n₁ = (0.0953 mol)(1.0 L)/(0.064 mol) = 1.489 L ≅ 1.50 L.

Chemistry question! Please help!

Answers

When a solid (solute) comes in contact with the liquid (solvent), the solute goes about C) dissolution, in which the solid dissolves into the liquid.

~

As this is with regards to solute and solvent, the solid will eventually dissolve in the liquid. The answer is C. dissolution.

Must show work for questions, if possible. (Please also explain, I don't understand)

1. A gas absorbs 0.0 J of heat and then performs 91.3 J of work. The change in internal energy of gas is

2. Two metals of equal mass with different heat capacities are subjected to the same amount of heat. Which undergoes the smallest change in temperature?

3. 30.0 mL of pure water at 280. K is mixed with 50.0 mL of pure water at 340 K. What is the final temperature?​

Answers

Answers:

1. D) 91.3 J

2. A) The metal with the higher specific heat capacity

3. B) 318 K

Step-by-step explanation:

1. E, q, w

ΔE = q + w

By convention, anything leaving the system is negative and anything entering the system is positive.

q = 0.0 J

w = -91.3 J

E = 0.0 - 91.3 = -91.3 J

2. Specific heat capacity

q = mCΔT

C = q/(mΔT)

If q and m are the same for each metal, then

ΔT ∝ 1/C = k/C  

As C increases, ΔT decreases.

Thus, the metal with the higher specific heat capacity will have the smaller temperature change.

3. Temperature on mixing

There are two heat flows in this problem.

Heat gained by cold water + heat lost by hot water = 0

                      q₁                    +                 q₂                 = 0

                 m₁CΔT₁                +             m₂CΔT₂           = 0

                 m₁ΔT₁                 x +              m₂ΔT₂           = 0

Data:

m₁ = 30.0 g

T₁ = 280. K

m₂ = 50.0 g

T₂ = 340 K

Calculations:

ΔT₁ = T_f - Ti = T_f - T₁ = (T_f - 280.) K  

ΔT₂ = T_f - Ti = T_f - T₂ = (T_f - 340) K  

30.0(T_f - 280.) + 50.0(T_f - 340)   = 0

30.0T_f - 8400 + 50.0T_f - 17 000 = 0

                           80.0T_f - 25 400 = 0

                                          80.0T_f = 25 400

                                                  T_f =25 400/80.0

                                                  T_f = 318 K

The final temperature of the mixture is 318 K.

For a reaction system at equlibrium, le chateliers principle can be used to predict the

Answers

According to Le Chatelier's principle, adding additional reactant to a system will shift the equilibrium to the right, towards the side of the products. ... By Le Chatelier's principle, we can predict that the amount of methanol will increase, thereby decreasing the total change in CO.

Rank the following elements by effective nuclear charge, Zeff, for a valence electron. F LI Be B N

Answers

F > N > B > Be > Li. This ranking is based on the decreasing effective nuclear charge (Zeff) experienced by a valence electron in the listed elements.

The element lithium (Li) has the lowest effective nuclear charge. One valence electron is 2s orbital. The nucleus has three protons (atomic number 3), however the inner electrons in the[tex]1s^2[/tex] orbital shield the valence electron, reducing its effective charge.

The Beryllium (Be) follows. The 2s orbital has two valence electrons. Despite having a higher atomic number (4) than lithium, the presence of two inner electrons in the [tex]1s^2[/tex] orbital provides more shielding and a somewhat higher effective nuclear charge.

Boron (B): Three valence electrons in the [tex]2s^2 2p^1[/tex]configuration. Boron's nucleus has more protons (atomic number 5), making it more positive. Compared to beryllium, the [tex]2p^1[/tex] electron provides less shielding for the valence electron, but the [tex]1s^2[/tex] electrons still protect the [tex]2s^2[/tex] electrons.

Nitrogen has a higher effective nuclear charge than boron. One additional proton (atomic number 7) in its nucleus boosts its positive charge. The presence of three [tex]2p^2[/tex] electrons reduces the shielding effect on the valence electron, enhancing its nucleus attraction.

Fluorine (F) has the highest effective nuclear charge. Nine protons make its nucleus extremely positively charged. Seven [tex]2p^5[/tex] electrons reduce shielding and attract the valence electron to the nucleus, resulting in the highest effective nuclear charge. Therefore, F > N > B > Be > Li is the decreasing order.

Learn more about effective nuclear charge, here;

https://brainly.com/question/12369639

#SPJ12

Final answer:

The effective nuclear charge (Zeff) typically increases from left to right across a period in the periodic table. Therefore, for the elements F, Li, Be, B, and N, the rank order by Zeff, from lowest to highest, would be: Li < Be < B < N < F.

Explanation:

The concept being asked here involves effective nuclear charge (Zeff), which highly depends on position in the periodic table. Generally, Zeff increases from left to right across a period. So, for a valence (outermost) electron in the elements you provided: F, Li, Be, B, and N, we would expect this trend to hold. The effective nuclear charge can be thought of as the net positive charge experienced by an electron in an atom. Inner electrons shield outer electrons from the full charge of the nucleus, leading to this effective reduction in charge.

Thus, using that knowledge, we can rank these elements as follows: Li < Be < B < N < F. This order means that Fluorine (F), being the furthest right on the periodic table, has the highest effective nuclear charge. The atomic nucleus of Fluorine exerts a stronger pull on its valence electron relative to the other elements that have been listed.

Learn more about Effective Nuclear Charge here:

https://brainly.com/question/33631338

#SPJ3

What is the ph of pure water at 40.0°c if the kw at this temperature is 2.92 × 10-14?

Answers

Answer: pH = 6.77

Explanation:

1) Chemical equilibrium

2 H₂O (l) ⇄ H₃O⁺ (aq) + OH⁻ (aq)

2) Equilibrium constant, Kw

Kw = [H₃O⁺] × [OH⁻]By stoichiometry [H₃O⁺] = [OH⁻]. Call it xKw = x²x² = 2.92 × 10⁻¹⁴ M²x = √ (2.92 × 10⁻¹⁴) = 1.709 × 10⁻⁷ M = [H₃O⁺]

3) pH

pH = - log [H₃O⁺] = - log (1.709 × 10⁻⁷) = 6.77
Final answer:

The pH of pure water at 40.0°C, given an autoionization constant (Kw) of 2.92 × 10-14, would be approximately 6.768. This value is derived from using the equations Kw=[H+][OH-] for the autoionization of water and pH = -log[H+] to calculate the pH.

Explanation:

The question asks about the pH of pure water at 40.0°C if the autoionization constant (Kw) at this temperature is 2.92 × 10-14. Kw is the product of the molar concentrations of H+ ions and OH- ions in water. At any given temperature, Kw remains constant. In pure water (or any neutral solution), [H+] = [OH-] and therefore, pH = pOH.

As mentioned, Kw = [H+][OH-] , so in neutral water [H+] = [OH-] = sqrt(Kw). Given that Kw is 2.92 *10^-14, we can calculate [H+] = sqrt(2.92 *10^-14) = 1.708 *10^-7 M.

The formula to find the pH is pH = -log[H+]. Substituting in, pH = -log(1.708 *10^-7) = 6.768 which is slightly on the acidic side because the ideal neutral pH in standard conditions (25°C) is 7.

This demonstrates that the pH of pure water decreases (becomes more acidic) as the temperature increases.

Learn more about pH of pure water here:

https://brainly.com/question/14468224

#SPJ12

A student is preparing to perform a series of calorimetry experiments. She first wishes to determine the calorimeter constant (Ccal) for her coffee cup calorimeter. She pours a 50.0 mL sample of water at 345 K into the calorimeter containing a 50.0 mL sample of water at 298 K. She carefully records the final temperature of the water as 317 K. What is the value of Ccal for the calorimeter? A student is preparing to perform a series of calorimetry experiments. She first wishes to determine the calorimeter constant (Ccal) for her coffee cup calorimeter. She pours a 50.0 mL sample of water at 345 K into the calorimeter containing a 50.0 mL sample of water at 298 K. She carefully records the final temperature of the water as 317 K. What is the value of Ccal for the calorimeter? 99 J/K 21 J/K 76 J/K 28 J/K 19 J/K

Answers

Answer:

First choice: 99 J/K

Explanation:

1) First law of thermodynamic (energy balance)

Heat released by the the hot water (345K ) = Heat absorbedby the cold water (298 K) + Heat absorbed by the calorimeter

2) Energy change of each substance:

General formula:

     

Heat released or absorbed = mass × Specific heat × change in temperature

density of water: you may take 0.997 g/ ml as an average density for the water.

mass of water: mass = density × volume = 50.0 ml × 0.997 g/ml = 49.9 g

Specif heat of water: 1 cal / g°C

Heat released by the hot water:

       Heat₁ = 49.9 g × 1 cal / g°C × (345 K - 317 K) = 49.9 g × 1 cal / g°C × (28K)

Heat absorbed by the cold water:

       Heat₂ = 49.9 g × 1 cal / g°C × (317 K - 298 K) = 49.9 g × 1 cal / g°C × (19K)

Heat absorbed by the calorimeter

       Heat₃ = Ccal × (317 K - 298 K) = Ccal × (19K)

4) Balance

Heat₁ = Heat₂ + Heat₃

49.9 g × 1 cal / g°C × (28 K) = 49.9 g × 1 cal / g°C × (19 K) + Ccal × (19 K)

Solve for Ccal

Ccal = [49.9 g × 1 cal / g°C × (28 K) - 49.9 g × 1 cal / g°C × (19 K) ] / 19K

Ccal = 23.6 cal/ K

Convert to cal / K to Joule / K

1 cal = 4.18 Joule

       23.6 cal / K × 4.18 J / cal = 98.6 J/K

Which rounded to 2 signficant figures leads to 99 J/k, which is the first choice.

Calorimetry is the measurement technique, in which heat of the chemical reactions and heat capacity is measured. The value of Ccal for the calorimeter is 99 J/K.

According to the first law of thermodynamics, the energy cannot be created nor be destroyed. It can be transferred from one form to another.

Such as:

Heat released by the the hot water at 345K  = Heat absorbed by the cold water at 298 K + Heat absorbed by the calorimeter

Also, from the formula, it can be calculated as:

Heat or H = mass × Specific heat × change in temperature

Given that,

Density of water = 0.997 g/ mlMass of water = density × volume = 50.0 ml × 0.997 g/ml = 49.9 gSpecific heat = 1 cal/ g Celcius

Now, substituting the values, heat released by the water will be:

 Heat₁ = 49.9 g × 1 cal / g°C × (345 K - 317 K) = 49.9 g × 1 cal / g°C × (28K)

Similarly, heat absorbed by the cold water will be:

Heat₂ = 49.9 g × 1 cal / g°C × (317 K - 298 K) = 49.9 g × 1 cal / g°C × (19K)

Now, the overall heat absorbed by the calorimeter will be equal to:

Heat₃ = Ccal × (317 K - 298 K) = Ccal × (19K),

The value of Ccal will be:

Ccal = [49.9 g × 1 cal / g°C × (28 K) - 49.9 g × 1 cal / g°C × (19 K) ] / 19K Ccal = 23.6 cal/ K or 98.6 J/K (in Joules)

Therefore, the Ccal for the calorimeter will be equal to approximately 99 J/K.

To know more about calorimeter, refer to the following link:

https://brainly.com/question/15187880?referrer=searchResults

Calculate the ph of a solution containing 0.75 m lactic acid and 0.25 m sodium lactate. recalculate after the addition of 0.05ml of hcl

Answers

pH= pKa+log[A-]/[HA]

pKa=-log(Ka)

-log(1.4/10^-4) (the Ka of lactic acid)

pKa=3.85

pH=3.85+log (0.25/.75)

pH=3.37

HCl is an acid, so the 0.05M HCl is added to the acid and subtracted from the base

pH= 3.85+ log(0.24/0.76)

pH=3.35 after addition of HCl

Units used to measure the rate of electron flow

Answers

SI units = ammeters, their called amps

Which central atom hybridization would you expect in the series bh−4, ch4, nh+4?

Answers

Expected:

sp³ in all three molecules.

Explanation

The hybridization of the central atom is related to the number of electron domains around that atom.

[tex]\begin{array}{c|c|c}\textbf{Number of Electron Domains} & \textbf{Hybridization}&\textbf{Example}\\ 2 & \text{sp} & \text{C as in CO}_2\\ 3 & \text{sp}^{2} & \text{C in H}_2\text{C}=\text{CH}_2\\ 4 &\text{sp}^{3} & \text{C as in CH}_4\end{array}[/tex].

What is an electron domain?

An atom bonded to the central atom counts as one electron domain. That atom counts as one electron domain regardless of the bond order. One single bond counts as one electron domain. One double bond counts as one electron domain. One triple bond counts as one electron domain.A lone pair of electrons count as one electron domain.

How many electron domains in BH₄⁻, CH₄, and NH₄⁺?

BH₄⁻: Four H atoms are bonded to the central B atom. That ensures an octet for the central B atom. No lone pairs are needed. Four electron domains from the four bonded atoms. sp³ hybridization.CH₄: Four electrons domains with four H atoms and no lone pair. sp³ hybridization.NH₄⁺: Four electrons with four H atoms and no lone pair. sp³ hybridization.

anyone know how to calculate moles? for chem.

If the atmospheric pressure in the laboratory is 1.2 atm, how many moles of gas were in each syringe?
^ this is my question

Trial 1:
volume for syringe: 4.2 ml
temperature: 0.9 - C

Trial 2:
volume for syringe: 4.1 ml
temperature: 0.9 - C

if you could also explain well I would appreciate it!

Answers

Answer:

Trial 1 : n = 0.0002241 moles

Trail 2 :  n = 0.0002188 moles

Explanation:

Let's bring out the data in the question;

Pressure (P) = 1.2 atm

Number of moles (n) = ?

Both trials contain different values of Volume (V) and temperature (T)

The equation that relates all four parameters (V, T, P and n) is the ideal gas equation. It is given as;

PV = nRT where R = gas constant = 0.0821 L atm K−1 mol−1

Soving for n, we have;

n = PV / RT

Trial 1

Volume (V) = 4.2 ml = 0.0042 L (Converting to L by dividing by 1000)

Temperature (T) = 0.9 + 273 = 273.9K (Converting to Kelvin temperature)

n = (1.2 * 0.0042) / (0.0821 * 273.9)

n = 0.00504 / 22.48719

n = 0.0002241 moles

Trial 2

Volume (V) = 4.1 ml = 0.0041 L (Converting to L by dividing by 1000)

Temperature (T) = 0.9 + 273 = 273.9K (Converting to Kelvin temperature)

n = (1.2 * 0.0041) / (0.0821 * 273.9)

n = 0.00492 / 22.48719

n = 0.0002188 moles

What is the kinetic theory

Answers

The body of theory which explains the physical properties of matter in terms of motion so I think it’s A

Final answer:

The kinetic molecular theory is an atomic description of gaseous, liquid, and solid matter. It states that these molecules are in constant, random motion with kinetic energy dependent on temperature. This theory is fundamental in explaining properties of matter including the ideal gas law.

Explanation:

The kinetic molecular theory is a scientific model that explains the behavior of gases. According to this theory, gases are comprised of a large number of tiny molecules, which are widely separated and in constant, random motion. These molecules engage in elastic collisions with each other and the walls of their container. The speed of these molecules, and consequently their kinetic energy, is determined by their absolute temperatures.

This theory is also extended to explain the properties of solids and liquids in terms of continuous random motion of atoms and molecules. In other words, the kinetic molecular theory is essentially an atomic description of matter, providing detailed explanations for various phenomena such as temperature, pressure, and heat transfer, among others.

Moreover, the ideal gas law ties in closely with the kinetic molecular theory. It can be expressed in terms of the mass of the gas's molecules and the average of the molecular speeds squared.

Learn more about Kinetic Molecular Theory here:

https://brainly.com/question/15013597

#SPJ3

Based on the kinetic molecular theory, which of the following statements is correct about the particles in a sample of gas? They have negligible kinetic energy. There is negligible force of attraction between them. The space between them decreases with increase in temperature. Their average kinetic energy decreases with increase in temperature.

Answers

Answer:

There is negligible force of attraction between them.

Explanation:

According to kinetic molecular theory of gases:

a) They have high kinetic energy so the molecules show random motion.

b) The space between them increases with increase in temperature. With increase in temperature, the kinetic energy increases and the molecules move farther from each other, volume increases.

c) the average kinetic energy increases with increase in temperature

Thus only true statement is:

There is negligible force of attraction between them.

Based on the kinetic molecular theory, there is a negligible force of attraction between the particles in the sample of gas.

The correct statement is option B.

What kinetic molecular theory?

Kinetic molecular theory state that the particles of gas are large spherical and are in constant motion and have a perfectly elastic collision.

This theory can explain both Boyle's law and Charles's law.

Thus, the correct option is B, There is a negligible force of attraction between them.

Learn more about kinetic molecular theory, here:

https://brainly.com/question/8369832

Which of the following units is used to express electrical charge? Question 2 options: Newton Coulomb Joule

Answers

The coulomb whose symbol is (C),  is used to express charge. It is the SI unit of  electric charge.

1 C is equivalent to charge carried by 6.24×10¹⁸ electrons. Although electrons are negatively charged, the Coulomb expresses both positive and negative charges.

Answer: Coulomb

Explanation:

[tex]Q=I\times t[/tex]

where Q= quantity of electricity

I = current in amperes

t= time in seconds

Thus charge is in coulomb. 1 coloumb of charge appears whe 1 ampere current is passed for 1 second.

Newton is the unit of force.

[tex]1kgms^{-2}=1Newton(N)[/tex]

Joule is the unit of energy.

[tex]1kgm^2s^{-2}=1 Joule[/tex]

How are science and technology related? A. Science is a branch of technology. B. Science is the application of technological knowledge. C. Technology is the application of the knowledge gained by science.

Answers

The answer should be C. Technology is the application of the knowledge gained by science.

Answer:

C. Technology is the application of the knowledge gained by science.

Explanation:

Science is about the discovery of some novel compounds such as cancer curing drugs or understanding the kinetics of reaction mechanisms. Technology takes the discovery made by science and upscales the process and makes it more efficient. Technology involves stem cell engineering to create clones or making pesticide resistant plants.

What is the freezing point of a solution of 0.5 mol of LiBr in 500 mL of water? (Kf = 1.86°C/m) –1.86°C –7.44°C –5.58°C –3.72°C

Answers

Answer:

Last choice: - 3.72°C

Explanation:

The freezing point depression in a solvent is a colligative property: it depends on the number of solute particles.

The equation to predict the freezing point depression in a solvent is:

ΔTf = Kf × m × i

Where,

ΔTf is the freezing point depression of the solvent,m is the molality,Kf is the cryoscopic molal constant of the solvent, and i is the Van'f Hoff factor, which is the number of ions produced by each unit formula of the ionic compound.

The calcualtions are in the attached pdf file. Please, open it by clicking on the image of the file.

Answer: -1.86

Explanation: Got it right on edg

an unknown element is a solid at room temperature, is highly conductive, and is easily hammered into thin sheets. it is most likely a:

A. Metal
B. Non-metal
C. Metalloid

Answers

A. Metal

Metals are very conductive, malleable, and almost all of them are solid at room temperature.

which of the following would the kinetic theory address

Answers

The Kinetic Theory of gases states that the gases are made of small particles (atoms or molecules) which are in random motion.

Postulates of Kinetic Molecular Theory of gases:

1. All gases are made up of a large number of minute particles of molecules.

2. The molecules are separated from one another by large distances, called as intermolecular spaces.

3. The molecules are in the state of rapid motion in all directions. They collide with each other and the walls of the container, and thus change their directions.

4. There is no loss of energy when the molecules collide among themselves and the wall of the container.

5. The molecules are independent of each other as the molecules has no forces of interaction (repulsive or attractive) between molecules.

6. The pressure exerted by the gas is due to the collision of the molecules with the walls of the container per unit area.

7. The average Kinetic energy of the gas molecules is directly propotional to the absolute temperature.

Answer: vibrating molecules

Explanation:

a p e x

[Standard Enthalpy Formation]

Remember to show work and explain.

1. Use the equation below to determine the amount of energy released when 78.0g Of H2S react with excess SO2.

2. How many grams of 2AgNO3 are needed to react to produce 567kJ of energy in the following reaction?​

Answers

Answer:

1. 65.1 kJ; 2. 558 g

Step-by-step explanation:

1.

M_r: 34.08

        2H₂S+ SO₂ ⟶ 3S + 2H₂O ; ΔH = -56.9 kJ

Treat the heat as if it were a product in the equation. Then use the molar ratio (56.9 kJ/2 mol H₂S) in the usual way.

Moles of H₂S = 78.0 g H₂S × (1 mol H₂S/34.08 g H₂S) = 2.289 mol H₂S

Amount of heat = 2.289 mol H₂S × (56.9 kJ/2 mol H₂S) = 65.1 kJ

The reaction releases 65.1 kJ of energy.

2.

M_r:   169.87

         2AgNO₃ + BaCl₂ ⟶ 2AgCl + Ba(NO₃)₂; ΔH = -345 kJ

Moles of AgNO₃ = 567 kJ × (2 mol AgNO₃/345 kJ = 3.287 mol AgNO₃

Mass of AgNO₃ = 3.287 mol AgNO₃ × (169.87 g AgNO₃/1 mol AgNO₃)

= 558 g AgNO₃

You need 558 g of AgNO₃.

to produce 4.00 L of a 250 mM solution of sodium hydroxide, how many grams of naOH must be dissolved?

Answers

Multiply the volume in liters (4.00L) by the concentration of the solution in molar (0.250M) to calculate the number of moles of soluto that you need, then multiply the number of moles by the molar mass of sodium hydroxide (39.99 g/mol) to calculate the mass.

4.00L x 0.250 M x 39.99g / 1L = 39.99g

Basically you need one mol of NaOH (39.99g) dissolved in 4 liters of solution.

Answer: [tex]1.56\times 10^{-3}g[/tex]

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]

where,

Molarity = 250mM = [tex]250\times 10^{-3}M[/tex]

n= moles of solute  

[tex]V_s[/tex] = volume of solution in ml = 4L = 4000 ml

[tex]{\text {moles of solute}}=\frac{\text {given mass}}{\text {molar mass}}=\frac{xg}{40g/mol}=0.025x[/tex]

Now put all the given values in the formula of molarity, we get

[tex]250\times 10^{-3}=\frac{0.025\times x\times 1000}{4000ml}[/tex]

[tex]250\times 10^{-3}=\frac{0.025\times x\times 1000}{4000ml}[/tex]

[tex]x=1.56\times 10^{-3}g[/tex]

Therefore, the [tex]1.56\times 10^{-3}g[/tex] of NaOH must be dissolved.

____________ are compounds that contain a carbon-carbon triple bond.

Answers

Answer:

Alkynes are compounds that contain a carbon-carbon triple bond.

Explanation:

The simplest organic compounds are formed excluseively by carbon and hydrogen. They are named hydrocarbons.

There are 3 main types of hydrocarbons, namely alkanes, alkenes and alkynes.

Alkanes posses only single bonds and have general formula Cₙ H₂ₙ ₊ ₂. E.g.: CH₃ - CH₃ (ethane).

Alkenes have one or more double bonds between pairs of carbon atoms. E.g.: CH₃ - CH = CH₂ (propene).

Alkynes contain one or more triple bonds between pairs of carbon atoms. E.g.: CH ≡ CH (ethyne or acethylene).

Both alkenes and alkynes are named unsaturated hydrocarbons, because they have less hydrogen atoms than they could (if they only hade single bonds),  while alkanes are saturated hydrocarbons.

What does each variable stand for in PV=nRT?
Thank you.

Answers

Hello there!

Let's explain to you the different variables in the PV=nRT equation:

PV=nRT:

P = Pressure

V = Volume

n = Moles (number of moles)

R = Gas Constant (universal)

T = Temperature

This is the ideal use of the gas law.

When calculating these different variables, its units are:

P = ATM (atmospheres)

V = L (liters)

n = mol (Moles)

R = J (Joule)

T= K (Kelvin)

Atoms with an electric charge come charged by gaining or losing

Answers

Is the atoms of electric

Why will clay weather the fastest out of several types of soil?

Answers

certain types of rock, like granite, are very resistant to weathering. Igneous rocks tend to weather slowly because it is hard for water to penetrate them. Other types of rock, like limestone and marble are easily weathered because they dissolve easily in weak acids.

Question 2(Multiple Choice Worth 3 points)
(07.05 MC)

The table shows the concentration of a reactant in the reaction mixture over a period of time.


Reactant Concentration
Time Concentration
0 s 1.8 M
210 s 1.2 M
450 s 0.8 M
580 s 0.6 M
720 s 0.4 M


What is the average rate of the reaction over the first 580 seconds?
1.6 × 10−3
1.9 × 10−3
2.0 × 10−3
2.2 × 10−3

Answers

Answer:

2.0 × 10−3

Explanation:

this is the correct answer, i don't know why people gave the other answer 3/5 stars because that answer and work was correct.

The average rate of reaction for the first 580 seconds is 2.0 × 10−3 M/s.

What is average rate of reaction?

The average rate is defined as the ratio of the change in concentration to the time taken. We are required here to find the average rate of the reaction over the first 580 seconds.

Hence, we have;

average rate = 1.8 M - 0.6 M/580 s - 0 s = 1.2 M/580 s  = 2.0 × 10−3 M/s

Hence, the average rate of reaction for the first 580 seconds is 2.0 × 10−3 M/s.

Learn more about average rate of reaction: https://brainly.com/question/11334504

The nucleus of an atom holds 4 neutrons and 4 protons, how many electrons does it have

Answers

It has 4 electrons, because the number of protons and the number of electrons must be equal.

When 1,4-dimethylcyclohepta-1,3-diene is treated with hbr at elevated temperature, the 1,2-adduct predominates, rather than the 1,4-adduct. choose the correct explanation from below?

Answers

Most likely, the production of the 1,4-adduct yields a less-substituted alkene in this situation. Following the 1,2-adduct pathway ensures that the remaining double bond is stabilized by the peripheral methyl group (trisubstituted), rather than making the new double bond disubstitited.

Hope this helps!

All faculty members are happy to see students help each other. Dumbledore is particularly pleased with Hermione. Though, it should be mentioned that students should not simply copy off each other. You will not learn anything that way. Snape glares at Ron... Ron slouches in his chair. Snape thinks it’s time for a harder problem. How many milligrams of magnesium reacts with excess HCl to produce 31.2 mL of hydrogen gas at 754 Torr and 25.0◦C. The hydrogen is produced by the following reaction: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) Express your answer in milligrams

Answers

Answer:

[tex]m_{Mg}=30.8mgMg[/tex]

Explanation:

Hello,

Based on the given chemical reaction, as 31.2 mL of hydrogen are yielded, one computes its moles via the ideal gas equation under the stated conditions as shown below:

[tex]n_{H_2}=\frac{PV}{RT}=\frac{754torr*\frac{1atm}{760torr}*0.0312L}{0.082 \frac{atm*L}{mol*K}*298.15K}=1.27x10^{-3}molH_2[/tex]

Now, since the relationship between hydrogen and magnesium is 1 to 1, one computes its milligrams by following the shown below proportional factor development:

[tex]m_{Mg}=1.27x10^{-3}molH_2*\frac{1molMg}{1molH_2}*\frac{24.305gMg}{1molMg}*\frac{1000mgMg}{1gMg}\\m_{Mg}=30.8mgMg[/tex]

Best regards.

Other Questions
chemistry!! I need help with calculating the percent of hydrate and massinfo: A dry, empty crucible was obtained weighing 10.00 grams. The hydrate (BeSO4 4 H2O) was placed into this crucible and the total mass was recorded at 15.00 grams. After heating the hydrate to remove the water, the mass of the anhydrous compound and crucible was 12.94 grams. questions: a) Determine the mass of the original hydrate. b) Determine the mass of just the anhydrous salt. c) Calculate the number of moles of anhydrous salt using the molar mass of just BeSO4. d) Determine the mass of water lost. e) Calculate the number of moles of water lost using the molar mass of water. f) Determine the smallest whole number ratio of moles of water : moles of anhydrous salt. g) Did the experiment results corroborate with the formula BeSO4 4 H2O? What is the primary tool that congress uses to exercise some control over the fed? How does the construction of a market demand curve for a private good differ from that for a public good? Extended paragraph please hurry worth 20 points Victor faints at the sight of Elizabeths body: Life is obstinate and clings closest where it is most hated. For a moment only did I lose recollection; I fell senseless on the ground. Fainting in Romantic and Victorian texts is often seen as a feminine trait. What is the significance of Victor fainting at the sight of the murdered Elizabeth? In what ways has he been feminized by what has happened to him? The following were men who founded colonies in North America. (Select all that apply.) Why is a piece of music considered a form of persuasive argument? rewrite as an exponential functionln9=y Which term describes the time it takes for an object to complete one full cycle of motion on a spring? A. period B. frequency C. amplitude D. time E. force Which scenario is modeled by the equation (x)(0.6)=$86.46? What is the solution to x in -6x+7>1 Which sentence best explains how an allusion is the passage affects its meaning what is deuki pratha Which officer of the state is in charge of official records and documents and supervises elections? what is 2x + 10 = 20 What was the main reason that the United States adopted policies to stop the spread of communism around the world ? PLZ PLZ HELP WILL GIVE BRAINLIEST which of the following are square roots of the number below? check all that apply. 400A) 400^1/2B) 40C) -20D) 10E) 20F) -400^1/2 PLEASE ANSWER WILL MARK BRAINLIESTcarlos and maria are outside flying a kite. carlos has let 40 feet of string out for the kite which is flying directly over maria. how high above maria is the kite Which of the following was an effect of the Glorious RevolutionA.the overthrow of James IB.the signing of Magna CartaC.the assassination of Henry IVD.the passage of the English Bill of Rights Atomic physicists usually ignore the effect of gravity within an atom. To see why, we may calculate and compare the magnitude of the ratio of the electrical force and gravitational force Fe Fg between an electron and a proton separated by a distance of 3 m. What is the magnitude of the electrical force? The Coulomb constant is 8.98755 109 N m 2 /C 2 , the gravitational constant is 6.67259 1011 m3 /kg s 2 , the mass of a proton is 1.67262 1027 kg, the mass of an electron is 9.10939 1031 kg, and the elemental charge is 1.602 1019 C. Answer in units of N. What is the ratio of the magnitude of the electrical force to the magnitude of the gravitational force? Answer in units of N. Steam Workshop Downloader