Iridium is a component of cosmic dust that rains down upon the earth at a constant rate. Why did Luis Alvarez suggest measuring iridium levels in the K-T boundary?

Answer:

₉₂U²³⁸   →   ₉₀Th²³⁴  + ₂He⁴  + energy

Explanation:

Alpha decay:

Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4  and atomic number less than 2 as compared to parent atom the starting atom.

Properties of alpha radiation:

Alpha radiations can travel in a short distance.

These radiations can not penetrate into the skin or clothes.

These radiations can be harmful for the human if these are inhaled.

These radiations can be stopped by a piece of paper.

₉₂U²³⁸   →   ₉₀Th²³⁴  + ₂He⁴  + energy

Hydrogen is unique due to several factors: it doesn't belong definitively to any group, its electron is unshielded from its nucleus, it is the lightest element, it exists as a diatomic gas at room temperature, and it exhibits properties of both alkali metals and halogens.

Hydrogen is indeed unique among the elements for several reasons. Firstly, it is not really a member of any particular group on the periodic table. It is often placed with Group 1A (the alkali metals) because it has one electron in its outer shell like them, but it also exhibits properties similar to Group 7A (the halogens), as it needs one more electron to complete its shell. Secondly, its electron is not at all shielded from its nucleus, resulting in an unusual level of interaction between the two. Thirdly, hydrogen is the lightest element, which impacts its physical and chemical properties. Fourthly, it is the only element to exist at room temperature as a diatomic gas; in its natural state, hydrogen gas (H2) is made up of two hydrogen atoms bonded together. Finally, as already mentioned, it shares chemical properties with both alkali metals and halogens.

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To calculate the volume of silver nitrate solution required to precipitate all the Cl- ions as AgCl, use the concentration of Cl- ions in the solution and the stoichiometric ratio between Ag+ and Cl- ions. The volume of solution is equal to the volume of the silver nitrate solution.

To calculate the volume of a 0.22 M silver nitrate solution required to precipitate all the Cl- ions as AgCl, we need to determine the stoichiometric ratio between Ag+ and Cl- ions in the reaction. Since the balanced equation is Ag+ + Cl- → AgCl, the ratio is 1:1. We can use the concentration of Cl- ions in the solution to determine the volume of the silver nitrate solution needed.

The concentration of Cl- ions in the solution is reduced to half its initial value when AgNO3 and NaCl solutions are mixed. Given a concentration of 2.0 × 10^-4 M, after mixing, it becomes 1.0 × 10^-4 M. To calculate the volume of silver nitrate solution required, we can use the following equation:

Volume (L) = moles of Cl-/concentration of Cl-

Let's assume the volume of silver nitrate solution required is V liters: V = (moles of Cl-) / (1.0 × 10^-4 M)

To determine the moles of Cl-, we can use the equation:

moles of Cl- = concentration of Cl- × volume of solution (in liters)

Substituting the given concentration and volume:

moles of Cl- = 1.0 × 10^-4 M × V

Now, substituting the value of moles of Cl- in the volume equation:

V = (1.0 × 10^-4 M × V) / (1.0 × 10^-4 M)

This simplifies to V = V, meaning the volume of silver nitrate solution required to precipitate all the Cl- ions is equal to the volume of the solution.

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To precipitate all the Cl- ions in a 0.22 M silver nitrate solution as AgCl, an equal volume of the solution is required.

In order to determine the volume of a 0.22 M silver nitrate solution required to precipitate all the Cl- ions as AgCl, we can use stoichiometry. The equation for the reaction is:

Ag+ + Cl- → AgCl

From the balanced equation, we can see that 1 mole of AgCl is formed for every 1 mole of Cl- ions. Given the concentration of the silver nitrate solution, we can use the equation M1V1 = M2V2 to solve for the volume of the solution required.

Let V be the volume of the silver nitrate solution. Using the equation M1V1 = M2V2:

(0.22 M)(V) = (0.22 M)(V/2)

Simplifying the equation, we get:

V = V/2

Therefore, in order to precipitate all the Cl- ions, you would need to use an equal volume of the silver nitrate solution.

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Answer:

Answer in explanation

Explanation:

A renewable source of energy is an energy source that cannot be depleted. It is an energy source with constant abundance and hence it is always in abundance. What we are saying is that they are energy sources that cannot be used up. Although it might sometimes be that it is unavailable at some instances, this does not take away the fact that it is abundant and cannot be depleted, although the strength at different times may vary. Example of renewable energy sources include solar energy, wind energy, hydroelectric power source etc. These sources are never depleted and are in abundance.

Non renewable source of energy are those sources of energy that can be depleted. A good example of this can be seen in fossil fuels. Fossil fuels are usually burned to produce energy. They are used up in the process and it will require an additional amount of fossil fuel to be restocked for the energy to be continually supplied.

Explanation: Renewable resources can be replenished whenever you want, but non-renewable resources will keep dwindling down till there's nothing. For example, solar power is a renewable resource and will always be there because the sun will keep providing more solar power. Coal, on the other hand, is a non-renewable resource and won't always be there because coal takes a lot longer (300 million years) to form.

Answer:

Saccharose

Explanation:

Disaccharide Saccharose is formed by glucose and fructose, both monosaccharides are bound by their anomeric carbons (O-glucosidic), this is, both reducing carbons form the O-glucosidic bond, hence, they are not available to reduce Ag⁺ to Ag⁰

Answer:

14. B    15. D    16. C     17. B

Explanation:

The spontaneous reaction that occurs when the cell operates is shown below:

[tex]2Ag^{+} + Cd_{(s)}[/tex] ⇒[tex]2Ag_{(s)} + Cd^{2+}[/tex]

We need to select the correct option from the list below for the following questions.

(A) Voltage increases. (B) Voltage decreases but remains > zero. (C) Voltage becomes zero and remains at zero. (D) No change in voltage occurs. (E) Direction of voltage change cannot be predicted without additional information.

14. A 50-milliliter sample of a 2-molar [tex]Cd(NO_{3})_{2}[/tex] solution is added to the left beaker.

If a 50-milliliter sample of a 2-molar [tex]Cd(NO_{3})_{2}[/tex]  solution is added to the left beaker, the voltage decreases but its value remains greater than zero. The correct option is B

15. The silver electrode is made larger.

If the silver electrode is made larger, no change in the value of the voltage since we don't have the idea of the initial value. The correct option is D.

16. The salt bridge is replaced by a platinum wire.

If the salt bridge is replaced by a platinum wire, there will be no passage of electrons because electrons can't pass through a platinum wire. Therefore, the voltage will be zero and remains at zero. The correct option is C.

17. Current is allowed to flow for 5 minutes.

If current is allowed to flow for 5 minutes, the voltage decreases but its value remains greater than zero. The correct option is B.

A galvanic cell produces energy by a spontaneous redox reaction.

In galvanic or voltaic cell, energy is produced via a spontaneous redox reaction. The redox reaction equation of this reaction is;  2Ag^+ + Cd(s) ---> 2 Ag(s) + Cd^2+.

The answers to the questions are as follows;

14) When we add 50-milliliter sample of a 2-molar solution of cadmium nitrate, the voltage will decrease but remains greater than zero.

15) The voltage will remain the same after the increase in the size of the silver electrode because its initial value is unknown.

16) The voltage will remain at zero if the salt bridge is replaced by a platinum wire since current can not pass through

17) The voltage will decrease if current flows for five minutes.

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Answer:

[tex]H_2SO_4_{(aq)}+2LiOH_{(aq)}\rightarrow H_2O_{(l)}+Li_2SO_4_{(aq)}[/tex]

[tex]2H^+_{(aq)}+2OH^{-}\rightarrow H_2O_{(l)}[/tex]

Explanation:

Complete ionic equation : In complete ionic equation, all the substance that are strong electrolyte and present in an aqueous are represented in the form of ions.

Net ionic equation : In the net ionic equations, we are not include the spectator ions in the equations.

Only the species which are present in aqueous state dissociate.

Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.

(a)

The balanced molecular equation will be,

[tex]H_2SO_4_{(aq)}+2LiOH_{(aq)}\rightarrow H_2O_{(l)}+Li_2SO_4_{(aq)}[/tex]

The complete ionic equation in separated aqueous solution will be,

[tex]2H^+_{(aq)}+SO_4^-_{(aq)}+2Li^+_{(aq)}+2OH^{-}_{(aq)}\rightarrow H_2O_{(l)}+2Li^+_{(aq)}+SO_4^-_{(aq)}[/tex]

In this equation the species present are, [tex]Li^+\text{ and }SO_4^-[/tex] are the spectator ions.

Hence, the net ionic equation contains specie is  

[tex]2H^+_{(aq)}+2OH^{-}\rightarrow H_2O_{(l)}[/tex]

Answer:

This question is incomplete. But the completed question is below

A sample of helium gas is in a closed system with a movable piston. The volume of the  gas sample is changed when both the temperature and the pressure of the sample are increased.  Where the initial temperature of the gas is 200K, initial pressure is 2.0 atm, initial volume is 500 mL, the final temperature is 300K and the final pressure of the gas sample is 7.0 atm.

What is the correct numerical setup for calculating the final volume of the helium gas sample?

P₁V₁/T₁ = P₂V₂/T₂ will be used in calculating the final volume.

And the final volume is 214.29 mL

Explanation:

The general gas equation will be used to calculate the final volume. The general gas equation is

P₁V₁/T₁ = P₂V₂/T₂

From the question

P₁ = 2.0 atm

T₁ = 200K

V₁ = 500 mL

P₂ = 7.0 atm

T₂ = 300K

V₂ = unknown

Hence, we have

2 × 500/200 = 7 × V₂/300

V₂ = [tex]\frac{2 * 500 * 300}{200 * 7}[/tex]

V₂ = 214.29 mL

The final volume of He gas sample has been 214.285 mL.

Helium has been assumed to be an ideal gas. The final volume of the gas with an increase in pressure has been given by:

[tex]\dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}[/tex]

Where, the initial pressure of gas, [tex]P_1=2\;\text{atm}[/tex]

The final pressure of gas, [tex]P_2=7\;\text{atm}[/tex]

The initial volume of gas, [tex]V_1=500\;\text{ml}[/tex]

The initial temperature of gas, [tex]T_1=200\;\text K[/tex]

The final temperature of gas, [tex]T_2=300\;\text K[/tex]

Substituting the values for the final temperature of He, [tex]V_2[/tex]:

[tex]\dfrac{2\;\times\;500}{200}=\dfrac{7\;\times\;V_2}{300}\\\\\dfrac{2\;\times\;500}{200}\;\times\;\dfrac{300}{7} = V_2\\\\V_2=214.285\;\rm ml[/tex]

The final volume of He gas has been 214.285 mL.

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Answer:

Rubber is made from long-chain molecules, called polymers, which are normally all scrunched up. When you stretch a rubber band, you  straighten the molecules and pull them apart, so the rubber gets longer. When you let go, cross-link bonds between the polymers help to snap them back into place. This is what makes an elastic material such as rubber (one that returns to its original shape and size) different from a plastic material (one that changes shape but doesn't go back exactly to how it was), which includes most metals as well as most plastics.

Explanation:

Rubber is made of polymers. When the elastic band is at rest, the molecules are entangled with each other and do not have a particular direction, but when the elastic is stretched, they all align. The molecules of the polymer are not stretched, they are aligned in a different way. Therefore, there is no difference in energy, but there is a difference in entropy. When the elastic band is released, all the polymers are randomly agitated by thermal movement, and lose their alignment, so they return to the tangled state, causing the elastic to contract. This is known as entropic force.

Final answer:

When you stretch a rubber band, you straighten the molecules and pull them apart, so the rubber gets longer. When you let go, cross-link bonds between the polymers help to snap them back into place.

Explanation:

Rubber bands stretch by straightening molecules and snapping back due to cross-link bonds, characteristics unique to polymers. Polymer chains' conformational changes give flexibility and the ability to return to the original shape, influenced by factors like chain length and side groups.

The long-chain structure of polymers makes them behave differently from other materials. These chains can undergo conformational change, providing flexibility and the ability to return to their original shape. The physical properties of a polymer depend on factors like chain length, side groups, branching, and cross-linking, impacting its strength and flexibility.

Answer:

See explanation and picture

Explanation:

Question is incomplete, however, I found this question on several sites and most of them, have the same substances, so I'm gonna do it with that example to give you a hint of how to do it with yours, in case, it's a different substance.

First, we have a ketone and another substance, with MgCl. This is tipically the Grignard reagent, and this is often used to produce a tertiary alcohol.

The mechanism and final product is the following (See attached picture).

When a reaction product is treated with water, different outcomes can occur such as acid-base reactions, hydrolysis reactions, or precipitation reactions. The specific product depends on the reactants and reaction conditions.

Without knowing the specific reactants, it is difficult to provide a detailed answer. In general, when a reaction product is treated with H2O (water), it can lead to various outcomes such as hydrolysis, formation of an acid or base, or precipitation of a solid. Some reactions that occur with water are:

The exact product will depend on the specific reactants and reaction conditions.

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Answer:

There are 3 elements (6;12) (19;39) and (82;207)

There are 3 isotopes (6;13) (19;41) and (82;206)

Explanation:

Step 1:

Isotopes have the same atomic number but a different mass number

The element with number 19 is Potassium

Potassium has a mass number of 39 g/mol

This is the element potassium and is not an element

41C has mass number of 41 g/mol and is an isotope

The element with number 6 is carbon

Carbon has a mass number of 12 g/mol

13C has a mass number of 13 g/mol and is an isotope

The element with number 82 is lead

Lead has a mass number of  207 g/mol

206Pb has a mass number of 206 g/mol and is an isotope

There are 3 elements (6;12) (19;39) and (82;207)

There are 3 isotopes (6;13) (19;41) and (82;206)

Answer:

Melting point of aqueous solution = -10.32 °C

Explanation:

[tex]\Delta T_f=i \times k_f \times m[/tex]

Where,

ΔT_f = Depression in freezing point

k_f = molal depression constant

m = molality

Formula for the calculation of molality is as follows:

[tex]m=\frac{Mass\ of\ solute\ (kg)}{molecular\ mass\ of\ solute \times mass\ of\ solvent}[/tex]

density of water = 1 g/mL

density = mass/volume

Therefore,

mass = density × volume

volume = 3 L = 3000 mL

Mass of water = 1 g/mL × 3000 mL

                        = 3000 g

[tex]Molality(m)=\frac{100\times1000}{18\times 3000} \\=1.85\ m[/tex]

van't Hoff factor (i) for MgCl2 = 3

Substitute the values in the equation (1) to calculate depression in freezing point as follows:

[tex]\Delta T_f=i \times k_f \times m\\=3\times 1.86 \times 1.85\\=10.32\ °C[/tex]

Melting point of aqueous solution = 0 °C - 10.32 °C

                                                          = -10.32 °C

Answer:

The melting point of the solution is - 1.953 °C

Explanation:

In an ideal solution, the freezing point depression is computed as follows:

[tex]ΔT_f = k_f \times b \times i [/tex]

where:

[tex]ΔT_f[/tex] is the freezing-point depression

[tex]k_f[/tex] is the cryoscopic constant, in this case is equal to 1.86

b is the molality of the solution

i is the van't Hoff factor, number of ion particles per individual molecule of solute, in this case is equal to 3

Molality is defined as follows:

b = moles of solute/kg of solvent

Moles of solute is calculated as follows:

moles of solute = mass of solute/molecular weight of solute

In this case there are 100 g of solute and its molecular weight is 35.5*2 + 24 = 95 g/mole. So, the moles are:

moles of solute = 100 g/(95 g/mol) = 1.05 moles

The mass of solvent is computed as follows:

mass of solvent = density of solvent * Volume of solvent

Replacing with the data of the problem we get:

mass of solvent = 1 kg/L*3 L = 3 kg

Finally, the molality of the solution is:

b = 1.05/3 = 0.35 mol/kg

Then, the freezing-point depression is:

[tex]ΔT_f = 1.86 \times 0.35 \times 3 [/tex]

[tex]ΔT_f = 1.953 C[/tex]

The freezing-point depression is the difference between the melting point of the pure solvent (here water) and the melting point of the solution. We know that the the melting point of water is 0 °C, then:

melting point of water - melting point of the solution = 1.953 °C

melting point of the solution  = 0 °C - 1.953 °C = - 1.953 °C

Answer:

The percent yield for the reaction is 63.7%

Explanation:

This problem can be solved, from different rules of three.

The reaction is:

2NH₃(g) + CO₂(g) → CH₄N₂O(s) + H₂O(l)

2 moles of ammonia, produce 1 mol of urea.

Mass / molar mass = moles

6.59g / 17.031 g/m = 0.387 moles

As ratio is 2:1, I will produce half a mole of urea.

(0.387 m . 1m)/ 2m = 0.193 m

Let's find out the mass.

Mass of urea = Moles of urea . molar mass of urea.

Mass = 0.193m .  60.056 g/m = 11.6 g

If the percent yield for the reaction was 100 %, we make 11.6 g, but I only obtained 7.40 g so let's calculate the new percent yield.

11.6 g ____ 100 %

7.40 g ___ (7.40g / 11.6g) .100 = 63.7 %

Answer:

Answer in explanation

Explanation:

A catalyst is a substance that alter the rate of a chemical reaction. It either speeds up the rate of the chemical reaction or slows down the rate of the chemical reaction. Hence, we say a catalyst can either work positively or negatively.

A catalyst will bring down the value of the activation energy. It reduces the minimum amount of energy needed for the reaction to kickstart. Hence we say it tends to create an alternative pathway for the chemical reaction to proceed.

When it speeds up the rate, it is otherwise known as a positive catalyst, otherwise it is a negative catalyst.

A catalyst does not have any business with the nature of the products or the reactants. Its work is simple, either hasten or slow down the rate of a chemical reaction.

A catalyst has no effect On the equilibrium position of a chemical reaction. This is to say its addition or subtraction has no effect on the position of a chemical reaction

Catalysis is the process by which a catalyst lowers the activation energy of a chemical reaction, thus increasing the reaction rate without changing the nature of the products. A catalyst does not shift the position of a reaction at equilibrium but enables the system to reach equilibrium more quickly.

What is Catalysis?

Catalysis refers to the process by which a catalyst increases the rate at which a chemical reaction occurs. A catalyst facilitates a chemical reaction without undergoing any permanent chemical change itself. It works by providing an alternative reaction pathway with a lower activation energy (Ea), which is the energy required to initiate the reaction. This lower activation energy means that more reactant molecules can effectively collide and react at a given temperature, thereby speeding up the reaction rate.

Effect on Activation Energy and Reaction Rate

The presence of a catalyst in a chemical reaction results in a lower activation energy barrier. This, in turn, means that a greater percentage of reactant molecules have enough energy to overcome this barrier and form products. Consequently, the reaction rate is increased since the reaction can proceed faster.

Does a Catalyst Change the Nature of the Products?

A catalyst does not affect the energy of the reactants or the products, nor does it alter the overall thermodynamics of the reaction. Therefore, it does not change the nature of the products of the reaction.

Adding a Catalyst to a Reaction in Equilibrium

When a reaction is in equilibrium, adding a catalyst will not shift the equilibrium position or alter the concentrations of reactants and products at equilibrium. Instead, it will increase the rate at which equilibrium is reached by speeding up both the forward and reverse reactions equally.

Answer:

I have no idea how to do this question its hard for me

Explanation:

All colors of visible light can eject electrons from cesium due to its low work function. For selenium, only light towards the blue/violet end of the spectrum (short wavelength, high energy) can eject electrons due to its higher work function.

The phenomenon discussed in question involves the photoelectric effect, which occurs when light of a certain wavelength strikes a metal and ejects electrons. The color of light that can eject electrons from a substance is dependent on the substance's work function, the minimum energy necessary to remove an electron from the substance.

Given Cesium's low work function (3.43 × 10^-19 J), it can be activated by a wide range of wavelengths, meaning that all visible colors of light, from red (long wavelength, low energy) to violet (short wavelength, high energy), can eject electrons from it.

However, with Selenium's higher work function (9.5 × 10^-19 J), only light with shorter wavelengths and therefore higher energy, will be able to eject electrons. This means that only light towards the blue/violet end of the spectrum will be able to eject electrons from this element.

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Answer:

Answer in explanation

Explanation:

The similarity between binary ionic and binary covalent substances is that they both contain only 2 elements each. This means there are two elements in the configuration of both. That is the similarity between them

Now the first difference I will like to mention is the way in which they are bonded. While ionic substances are formed through the transfer of electrons, covalent substances are formed through the sharing of electrons. This means that an element with an excess number of electrons transfer completely a number of electrons to an element that is deficient in electrons. This can be seen in the case of sodium and chlorine. The electron that is transferred is controlled only by the nucleus of the second electron. In the covalent bonding however, the electrons are shared and the electrons shared are controlled by the nuclei of both elements

Another difference is that while binary ionic compounds might dissolve only in polar solvents such as water, binary covalent compounds might only dissolve in non polar solvents such as benzene.

Answer:

Similarity: they involve the presence of both a cation and an anion.

Differences:

1. Electron giving is done in ionic compounds and electrons sharing is done in covalent compounds.

2. Stronger interactions in ionic compounds while weak interactions in covalent compounds.

Explanation:

Hello,

In this case, one similarity present between ionic and covalent compounds is that both of them involve the presence of both a cation and an anion which are positive and negative respectively; this is in order to allow the contituents to gather by bonding either ionically or covalently.

On the flip side, on the difference is that ionic compounds involve the giving of electrons since usually just the anion attain the octet while the covelent compounds allow electron sharing to allow both the cation and the anion to attain the octet.

Nevertheless, despite the electron sharing and giving fact, ionic compounds have stronger interactions bonding the cation and the anion than those covalent compounds have. Ionic interactions are electrostatic and covalent interactions are attractive which are by far weaker than those electrostatic.

Best regards.

Answer:

The answers are

The warmer temperatures at Zeke's destination caused the pressure in his tires to increase.

The warmer temperatures at Zeke's destination caused the pressure in his tires to increase.

The warmer temperatures at Zeke's destination caused the pressure in his tires to spread out equally.

Explanation:

Answer: Step 1, Isomerase.

Explanation:

Form the version of palmitic acid in the step one by changing the double bond within alpha and beta carbon by Isomerase.

B and C are Isomers, the molecule only differ in configuration.

Answer:

Which are positive?  D.

Which are negative? A. B. C.

Explanation:

Generally, entropy can be defined as the degree of randomness of a system. The entropy of any system increases with an increase in the number of moles of the system. Entropy also increases when there is a change of state from solid to liquid or liquid to gas. Therefore for the systems in the given question:

A pond freezes in winter

The degree of disorderliness decrease because there is a change of state from liquid to solid. Thus, ΔSsys is negative.

Atmospheric CO2 dissolves in the ocean

There is also decrease in randomness, thus, ΔSsys is negative.

An apple tree bears fruit

There is also decrease in randomness, thus, ΔSsys is negative.

A pond freezes in winter, atmospheric CO2 dissolves in the ocean, and an apple tree bears fruit are negative changes in Delta S.

Delta S is a measurement used in thermodynamics to calculate the modifications in the level of entropy.

In conclusion, a pond freezes in winter, atmospheric CO2 dissolves in the ocean, and an apple tree bears fruit are negative changes in Delta S.

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Answer: atoms

Explanation:

All matter is made up of smaller indivisible particles called atoms. These atoms are the smallest units of matter ACCORDING to the Dalton's Atomic theory.

Molecules are combined atoms, while cells and phospholipids are complex combination of atoms.

Therefore, atoms is the answer

Answer:

The molecular formula of this compound is C4H4N2O2

Explanation:

Step 1: Data given

Mass of the compound = 84 mg

The compound contains:

36 mg of Carbon

3 mg of hydrogen

21 mg of nitrogen

24 mg of oxygen

Molar mass of carbon = 12.01 g/mol

Molar mass of hydrogen = 1.01 g/mol

Molar mass of nitrogen = 14 g/mol

Molar mass of oxygen = 16 g/mol

Step 2: Calculate number of moles

Moles = mass / molar mass

Moles of carbon = 0.036 g/ 12.01 g/mol = 0.003 moles

Moles of hydrogen = 0.003 g/ 1.01 g/mol = 0.003 moles

Moles of nitrogen = 0.021 g/ 14 g/mol = 0.0015 moles

Moles of oxygen = 0.024 g/ 16 g/mol = 0.0015 moles

Step 3: Calculate mol ratio

We divide by the smallest amount of moles

C: 0.003 / 0.0015 = 2

H: 0.003 / 0.0015 = 2

N = 0.0015/0.0015 = 1

O = 0.0015/0.0015 = 1

The empirical formula is C2H2NO

The molecular mass of this empirical formula is 56 g/mol

Step 4: Calculate the molecular formula

We have to multiply the empirical formula by n

n = 112 g/mol / 56g/mol = 2

We have to multiply the empirical formula by 2

Molecular formula = 2*(C2H2NO) = C4H4N2O2

The molecular formula of this compound is C4H4N2O2

Answer: One (1) electron

Explanation:

Lithium is a group 1 element with an atomic number of 3. Thus, it has just 3 electrons and its electronic configuration is 1s2, 2s1

To become lithium ion salts, it gives off its lone electron thereby becoming Li+ with configuration of 1s2 with just 2 electrons left.

So, Li atom loses only ONE ELECTRON to become an ion

Explanation:

An ionic solution is when a compound's ions in an aqueous solution have dissociated. As you combine two aqueous solutions, a reaction occurs. This is when you find out whether or not a precipitate is going to form. A precipitate occurs when the ion reaction component in water is insoluble.The formation of a precipitate is an indication that a chemical change has occurred. for example if we mix clear solutions of silver nitrate and sodium chloride, sodium nitrate is formed which is a precipitate.

Answer:

The difference lies in the kind of bond involved.

Explanation:

An ionic solid is composed of a network of oppositely charged ions such as sodium chloride solid. An atomic solid is formed by covalent linkage of atoms of the same element to form a three dimensional solid structure such as in diamond and graphite. A molecular solid consists of discreet molecules held together by intermolecular forces. Examples of molecular solids include naphthalene and the fullerenes.

Final answer:

Crystalline solids are categorized into ionic, molecular, covalent network, and metallic solids, each with unique properties such as melting points and electrical conductivity. Understanding these categories helps predict material behaviors.

Explanation:

Understanding Crystalline Solids: Ionic, Molecular, Covalent Network, and Metallic

Crystalline solids are distinguished based on their bonding and structural properties. They fall into four main categories: ionic solids, molecular solids, covalent network solids, and metallic solids. Each type exhibits distinct properties in terms of melting point, electrical conductivity, solubility in water, and appearance.

Ionic solids are formed through the electrostatic attraction between ions, have high melting points, and conduct electricity only when melted or dissolved in water.

Molecular solids are composed of molecules held together by van der Waals forces, have relatively low melting points, and are poor conductors of electricity in all states.

Covalent network solids consist of atoms connected by covalent bonds into a continuous 3D network, have very high melting points, and typically do not conduct electricity.

Metallic solids are composed of metal atoms packed closely together, have variable melting points, and are good conductors of electricity and heat due to the free movement of electrons.

Solids can broadly be categorized into amorphous solids and crystalline solids, with the latter being further divided into the types discussed. Understanding these categories and their properties aids in predicting the behavior of different materials under various conditions.

Answer:

Explanation:

Specific heat capacity of iron is the amount of heat required to raise 1g of iron by 1 degree Celsius.

The formula is Q=mc∆T

Where Q is energy in joules.

M is mass in gram.

C is specific heat capacity in J/g°C.

∆T is change in temperature in degree Celsius

Q=1086.75joules

M=15.85g

C=?

∆T = final T-initial T(175-25)=150°c.

Q=Mc∆T

1086.75= 15.85×C×150

1086.85=2377.5c

C=1086.85÷2377.5

C=0.46J/g°C.

Answer:

A = 3.5 moles

Explanation:

In order to do this, we need first to write the innitial conditions. The reaction is as follow:

A(s) <-------> B(g) + C(g)

From here, we can write an expression for the equilibrium constant which is:

Kc = [B]*[C]

We don't take A in the expression, because is solid, and solid and liquids do not contribute in the equilibrium.

We know the concentration of B, which is the same for C, because the moles of C are coming from A when it's decomposed, so if B is 1.3 M we can assume C is the same.

Kc for this innitial condition is:

Kc = (1.3)*(1.3) = 1.69

Now, in the second part of reaction the volume is doubled, which means that concentrations are halved:

A: 4.8/2 = 2.4 M

B and C: 1.3/2 = 0.65 M

So conditions for the second part will be like this:

   A(s) <----> B(g) + C(g)   Kc = 1.69

I:   2.4           0.65   0.65

C:  -x              +x       +x

E: 2.4-x         0.65+x   0.65+x

Replacing in Kc we have:

1.69 = (0.65+x)²   solving for x here

√1.69 = 0.65+x

1.3 = 0.65+x

x = 1.3 - 0.65

x = 0.65 M

Therefore, the remaining moles of A would be:

A = 2.4 - 0.65

[A] = 1.75 M

moles A = 1.75 * 2 = 3.5 moles

Answer:

a abd b

Explanation:

Answer:

all of them

Explanation:

correct on edge

Answer:

[tex]1.7742\times 10^{-3} mol/L[/tex] is the molar concentration of Cu(II) ions in the unknown solution.

Explanation:

Using Beer-Lambert's law :

Formula used :

[tex]A=\epsilon \times C\times l[/tex]

where,

A = absorbance of solution

C = concentration of solution

l = length of the cell =

[tex]\epsilon[/tex] = molar absorptivity of solution

A Beer's law plot is between absorbance and concentration.

[tex]\frac{A}{c}=Slope(m)=\epsilon\times l[/tex]

We have:

A = 0.55

The slope of the Beer's law plot = m = 310 L/mol

So, the concentration of the solution is:

[tex]c=\frac{A}{m}=\frac{0.55}{310 L/mol}=1.7742\times 10^{-3} mol/L[/tex]

[tex]1.7742\times 10^{-3} mol/L[/tex] is the molar concentration of Cu(II) ions in the unknown solution.

Using Beer's law and the given slope and absorbance values, the molar concentration of Cu2+ in the solution is approximately 1.77 * [tex]10^{-3[/tex] M.

Beer's law, also known as the Beer-Lambert law, establishes a linear relationship between the absorbance of a species in a solution and its concentration. The equation for Beer's law is A = εlc, where A is absorbance, ε is the molar absorptivity (given by the slope in this case), l is the path length (assumed to be 1 cm here), and c is the concentration. In your case, the slope is 310 L/mol, and you have measured an absorbance of 0.55.

To find the concentration of Cu2+ in the solution, we rearrange the Beer's law equation to c = A / εl. Substituting in your values, we get c = 0.55 / (310 L/mol * 1 cm), which simplifies to c = 0.00177 mol/L or 1.77 *  [tex]10^{-3[/tex]  M. So the molar concentration of Cu2+ in the unknown solution is approximately 1.77 *  [tex]10^{-3[/tex]  M.

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Answer:

It is called an antidiurectic hormone

Answer:

1 M

Explanation:

Magnesium chloride will furnish chloride ions as:

[tex]MgCl_2\rightarrow Mg^{2+}+2Cl^-[/tex]

Given :

Moles of magnesium chloride = 0.20 mol

Thus, moles of chlorine furnished by magnesium chloride is twice the moles of magnesium chloride as shown below:

[tex]Moles =2\times 0.20\ moles[/tex]

Moles of chloride ions by magnesium chloride = 0.40 moles

Potassium chloride will furnish chloride ions as:

[tex]KCl\rightarrow K^{+}+Cl^-[/tex]

Given :

Moles of potassium chloride = 0.10 moles

Thus, moles of chlorine furnished by potassium chloride is same as the moles of potassium chloride as shown below:

Moles of chloride ions by potassium chloride = 0.10 moles

Total moles = 0.40 + 0.10 moles = 0.50 moles

Given, Volume = 500 mL = 0.5 L (1 mL = 10⁻³ L)

Concentration of chloride ions is:

[tex]Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}[/tex]

[tex]Molarity_{Cl^-}=\frac{0.50}{0.5}[/tex]

The final concentration of chloride anion = 1 M

The concentration of the chloride ion, Cl¯ in the solution is 1 M

To obtain the answer to the question given above, we'll begin by calculating the number of mole of chloride ion, Cl¯ produced by each compound in the solution. This can be obtained as follow:

MgCl₂(aq) —> Mg²⁺(aq) + 2Cl¯(aq)

From the balanced equation above,

1 mole of MgCl₂ produced 2 moles of Cl¯.

Therefore, 0.2 mole of MgCl₂ will produce = 0.2 × 2 = 0.4 mole of Cl¯

KCl(aq) —> K⁺(aq) + Cl¯(aq)

From the balanced equation above,

1 mole of KCl produced 1 mole of Cl¯

Therefore,

0.1 mole of KCl will also produce 0.1 mole of Cl¯.

Next, we shall determine the total mole of Cl¯ in the solution.

Mole of Cl¯ from MgCl₂ = 0.4 mole

Mole of Cl¯ from KCl = 0.1 mole

Total mole of Cl¯ = 0.4 + 0.1

Finally, we shall determine the concentration of Cl¯ in the solution.

Total mole of Cl¯ = 0.5 mole

Volume = 500 mL = 500 / 1000 = 0.5 L

Concentration = mole / Volume

Concentration of Cl¯ = 0.5 / 0.5

Therefore, the concentration of Cl¯ in the solution is 1 M

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