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4 years ago

What two elements constitute about three fourths of earth's solid surface?

1 answer:

6 0

The two elements that constitute almost three fourths of the earth's solid surface are oxygen and silicon. Oxygen accounts for 46.6 percent of the Earth's crust, while silicon is 27.7 percent. The next more plentiful element on the Earth's crust is Aluminum.

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The molar solubilities of the following compounds (in mol/L) are:

IceJOKER [234]

Answer: The decreasing order of $K_{sp}$ is $AgSCN>AgBr>AgCN$

Explanation:

For AgBr:

The balanced equilibrium reaction for the ionization of silver bromide follows:

$AgBr\rightleftharpoons Ag^{+}+Br^-$

s s

The expression for solubility constant for this reaction will be:

$K_{sp}=[Ag^{+}][Br^-]$

We are given:

$s=7.3\times 10^{-7}mol/L$

Putting values in above equation, we get:

$K_{sp}=s\times s\\\\K_{sp}=s^2\\\\K_{sp}=(7.3\times 10{-7})^2=5.33\times 10^{-13}$

Solubility product of AgBr = $5.33\times 10^{-13}$

For AgCN:

The balanced equilibrium reaction for the ionization of silver cyanide follows:

$AgCN\rightleftharpoons Ag^{+}+CN^-$

s s

The expression for solubility constant for this reaction will be:

$K_{sp}=[Ag^{+}][CN^-]$

We are given:

$s=7.7\times 10^{-9}mol/L$

Putting values in above equation, we get:

$K_{sp}=s\times s\\\\K_{sp}=s^2\\\\K_{sp}=(7.7\times 10{-9})^2=5.93\times 10^{-17}$

Solubility product of AgCN = $5.33\times 10^{-17}$

For AgSCN:

The balanced equilibrium reaction for the ionization of silver thiocyanate follows:

$AgSCN\rightleftharpoons Ag^{+}+SCN^-$

s s

The expression for solubility constant for this reaction will be:

$K_{sp}=[Ag^{+}][SCN^-]$

We are given:

$s=1.0\times 10^{-6}mol/L$

Putting values in above equation, we get:

$K_{sp}=s\times s\\\\K_{sp}=s^2\\\\K_{sp}=(1.0\times 10{-6})^2=1.0\times 10^{-12}$

Solubility product of AgSCN = $1.0\times 10^{-12}$

The decreasing order of $K_{sp}$ follows:

$AgSCN>AgBr>AgCN$

4 0

4 years ago

Tidal water is pushed through turbine to generate electricity l. True or false?

iVinArrow [24]

The answer is true, this is how dams work as the water goes through ot it pushed the turbines inside to generate electricity.

I hope this helps.

3 0

3 years ago

Read 2 more answers

B. For the following questions, use the reaction NO2(g) N2(g) + O2(g), with ΔH = –33.1 kJ/mol and ΔS= 63.02 J/(mol·K).

Troyanec [42]

Answer:

I. Kindly, see the attached image.

II. The reaction is exothermic.

III. - 51.88 kJ/mol.

IV. The reaction is spontaneous.

Explanation:

I. Draw a possible potential energy diagram of the reaction. Label the enthalpy of the reaction.

Since the sign of ΔH is negative, the reaction is exothermic reaction.

In an exothermic reaction, the energy of the reactants is higher than that of the products.

Kindly see the attached image to show you the potential energy diagram of the reaction.

II. Is the reaction endothermic or exothermic? Explain your answer.

The reaction is exothermic reaction.

The sign of ΔH indicates wither the reaction is endothermic or exothermic one:

If the sign is positive, the reaction is endothermic.

If the sign is negative, the reaction is exothermic.

Herein, ΔH = - 33.1 kJ/mol, so the reaction is exothermic.

III. What is the Gibbs free energy of the reaction at 25°C?

∵ ΔG = ΔH - TΔS.

Where, ΔG is the Gibbs free energy change (J/mol).

ΔH is the enthalpy change (ΔH = - 33.1 kJ/mol).

T is the temperature (T = 25°C + 273 = 298 K).

ΔS is the entorpy change (ΔS = 63.02 J/mol.K = 0.06302 J/mol.K).

∴ ΔG = ΔH - TΔS = (- 33.1 kJ/mol) - (298 K)(0.06302 J/mol.K) = - 51.88 kJ/mol.

IV. Is the reaction spontaneous or nonspontaneous at 25°C?

The sign of ΔG indicates the spontaneity of the reaction:

If ΔG < 0, the reaction is spontaneous.

If ΔG = 0, the reaction is at equilibrium.

If ΔG > 0, the reaction is nonspontaneous.

Herein, ΔG = - 51.88 kJ/mol, so the reaction is spontaneous.

7 0

3 years ago

Am I closing the right one? Somebody help!

kolbaska11 [484]

Answer:

Yes you are choosing the right one because the sodium hydroxide with sulfuric acid is the correct answer

4 0

3 years ago

Read 2 more answers

Harry brought his first wand for 7 galleons. How much does that cost in British pounds

DanielleElmas [232]

the answer is 8.35 pounds

8 0

4 years ago