Chemistry 6th. Edition by John McMurry, Robert C. Fay | 9780321704955 | 0321704959

General Chemistry

Chemistry

255 SOLVED PROBLEMS

3 SOLVED PROBLEMS

Question: 14.3

PREDICTING THE DIRECTION OF ACID–BASE REACTIONS If you mix equal concentrations of reactants and products, which of the following reactions proceed to the right and which proceed to the left? (a) H2SO4(aq) + NH3(aq) →← NH4 + HSO4^-(aq) (b) HCO3^-(aq) + SO42^-(aq) →← HSO4^-(aq) + CO32^-(aq) ...

Verified Answer:

(a) In this reaction,

H_{2}SO_{4} and NH_...

Question: 16.6

CALCULATING ΔG° FOR A REACTION FROM ΔH° AND ΔS° Iron metal is produced commercially by reducing iron(III) oxide in iron ore with carbon monoxide: Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g) (a) Calculate the standard free-energy change for this reaction at 25 °C. (b) Is the reaction spontaneous under ...

Verified Answer:

(a) The following values of

ΔH°_{f}

...

Question: 16.7

CALCULATING ΔG° FOR A REACTION FROM ΔG°f VALUES (a) Calculate the standard free-energy change for the oxidation of ammonia to give nitric oxide (NO) and water. Is it worth trying to find a catalyst for this reaction under standard-state conditions at 25 °C? 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(l) ...

Verified Answer:

(a) ΔG° =

[4 ΔG°_{f}(NO) + 6 ΔG°_{f}(H...

Question: 16.8

CALCULATING FOR A REACTION UNDER NONSTANDARD-STATE CONDITIONS Calculate the free-energy change for ammonia synthesis at 25 °C (298 K) given the following sets of partial pressures: (a) 1.0 atm N2, 3.0 atm H2, 0.020 atm NH3 (b) 0.010 atm N2, 0.030 atm H2, 2.0 atm NH3 N2(g) + 3 H2(g) →← 2 NH3(g) ΔG° ...

Verified Answer:

(a) The value of

Q_{p}

Q_...

Question: 15.14

DECIDING WHETHER A PRECIPITATE WILL FORM WHEN SOLUTIONS ARE MIXED Will a precipitate form when 0.150 L of 0.10 M Pb(NO3)2 and 0.100 L of 0.20 M NaCl are mixed? ...

Verified Answer:

After the two solutions are mixed, the combined so...

Question: 18.3

DOING STOICHIOMETRY CALCULATIONS FOR REACTIONS OF IONIC HYDRIDES How many grams of barium hydride must be treated with water to obtain 4.36 L of hydrogen at 20 °C and 0.975 atm pressure? ...

Verified Answer:

n =

\frac{PV}{RT} = \frac{(0.975 atm)(4....

Question: 18.1

WRITING EQUATIONS FOR THE PREPARATION OF HYDROGEN Write a balanced equation for the production of synthesis gas from butane , C4H10(g) ...

Verified Answer:

C_{4}H_{10}(g) + 4 H_{2}O(g) → 9 H_{2...

Question: 17.9

USING STANDARD REDUCTION POTENTIALS TO CALCULATE AN EQUILIBRIUM CONSTANT Use the standard reduction potentials in Table 17.1 to calculate the equilibrium constant at 25 °C for the reactio 6 Br^-(aq) + Cr2O7^2-(aq) + 14 H^+(aq) → 3 Br2(aq) + 2 Cr^3+(aq) + 7 H2O(l) ...

Verified Answer:

Find the relevant half-reactions in Table 17.1, an...

Question: 17.6

USING THE NERNST EQUATION TO CALCULATE THE CELL POTENTIAL UNDER NONSTANDARD-STATE CONDITIONS Consider a galvanic cell that uses the reaction Zn(s) + 2 H+(aq) → Zn2+(aq) + H2(g) Calculate the cell potential at 25 °C when [H^+] = 1.0 M, [Zn^2+] = 0.0010 M, and PH2 = 0.10 atm. ...

Verified Answer:

The standard cell potential is E° =

E°_{Zn ...

Question: 17.5

PREDICTING WHETHER A REDOX REACTION IS SPONTANEOUS Predict from Table 17.1 whether Pb^2+(aq) can oxidize Al(s) or Cu(s) under standardstate conditions. Calculate E° for each reaction at 25 °C. ...

Verified Answer:

Pb^{2+}(aq)

is above Al(s) in the t...

Question: 0.5

A Calculation Using Significant Figures It takes 9.25 hours to fly from London, England, to Chicago, Illinois, a distance of 3952 miles. What is the average speed of the airplane in miles per hour? ...

Verified Answer:

First, set up an equation dividing the number of m...

Question: 6.3

Balancing a Chemical Equation Write a balanced equation for the reaction of element A (red spheres) with element B (blue spheres) as represented below: STRATEGY Balancing the reactions shown in graphic representations of this sort is just a matter of counting the numbers of reactant and product ...

Verified Answer:

3 \mathrm{~A}_2+9 \mathrm{~B}_2 \longrighta...

Question: 9.1

Calculate the work in kilojoules done during a reaction in which the volume expands from 12.0 L to 14.5 L against an external pressure of 5.0 atm. ...

Verified Answer:

w = -(5.0 atm)(2.5 L) = -12.5 L • atm

(-12....