Chen homework

Foundations of Chemistry I Fall 2022
Homework 5
Deadline: Wednesday October 19th 8:15am
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1. From Zumdahl 4.80 [2 pts]
Balance each of the following oxidation-reduction reactions by using the oxidation
states method.
a. C2H6(g) + O2(g) → CO2(g) + H2O(g)
b. Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g)
2. From Zumdahl 4.81 and 4.82 [4 pts]
Balance the following oxidation-reduction reactions using the half-reaction method.
a. Br−(aq) + MnO4−(aq) → Br2(l) + Mn2+(aq) (in acidic solution)
b. CH3OH(aq) + Cr2O72−(aq) → CH2O(aq) + Cr3+(aq) (in acidic solution)
c. Al(s) + MnO4−(aq) → MnO2(s) + Al(OH)4−(aq) (in basic solution)
d. Cl2(g) → Cl−(aq) + ClO−(aq) (in basic solution)
3. Zumdahl 4.126 [2 pts]
Consider reacting copper(II) sulfate with iron. Two possible reactions can occur, as
represented by the following equations.
copper(II) sulfate(aq) + iron(s) → copper(s) + iron(II) sulfate(aq)
copper(II) sulfate(aq) + iron(s) → copper(s) + iron(III) sulfate(aq)
You place 87.7 ml of a 0.500 M solution of copper(II) sulfate in a beaker. You then
add 2.00 g of iron filings to the copper(II) sulfate solution. After the reaction occurs,
you isolate 2.27 g of copper. Which equation above describes the reaction that
occurred? Support your answer.
4. Zumdahl 5.40 [2 pts]
A gas sample containing 1.50 moles at 25°C exerts a pressure of 400. torr. Some gas
is added to the same container, and the temperature is increased to 50.°C. If the
pressure increases to 800. torr, how many moles of gas were added to the
container? Assume a constant-volume container.
5. Zumdahl 5.29 [2 pts]
Consider the flask diagrammed below. What are the final partial pressures of H2 and
N2 after the stopcock between the two flasks is opened? (Assume the final volume is
3.00 L) What is the total pressure (in torr)?
6. Zumdahl 5.68 [2 pts]
Silane is the silicon analogue of methane (CH4). It is prepared industrially according
to the following equations:
Si(s) + 3HCl(g) -> HSiCl3(l) + H2(g)
4HSiCl3(g) -> SiH4(g) + 3SiCl4(l)
a. If 156 mL of HSiCl3 (d = 1.34 g/mL) is isolated when 15.0 L of HCl at 10.0 atm
and 35°C is used, what is the percent yield of HSiCl3?
b. When 156 mL pf HSiCl3 is heated, what volume of SiH4 at 10.0 atm and 35°C
will be obtained if the percent yield of the reaction is 93.1%?
7. Zumdahl 5.80 [2 pts]
Consider the following samples of gases at the same temperature.
Arrange each of these samples in order from lowest to highest for the
following properties (and give your reasoning).
a. Pressure
b. Average Kinetic Energy
c. Density
d. Root mean square velocity
Note: Some samples of gases may have equal values for these attributes.
Assume the larger containers have a volume twice the volume of the smaller
containers and assume the mass of an argon atom is twice the mass of a neon
atom.
8. Zumdahl 5.94 [2 pts]
Consider the following velocity distribution curves A and B.
a. If the plots represent the velocity distribution of 1.0 L of He(g) at STP versus
1.0 L of Cl2(g) at STP, which plot corresponds to each gas? Explain your
reasoning.
b. If the plots represent the velocity distribution of 1.0 L of O2(g) at temperatures
of 273 K versus 1273 K, which plot correspond to each temperature? Explain
your reasoning. Under which temperature condition would the O2(g) sample
behave most ideally? Explain.
9. Zumdahl 5.81 and 5.82 [2 pts]
Calculate the average kinetic energies and root mean squared velocities of CH4 and
N2 molecules at 273 K and 546 K.
Suggested additional problems (not required, not graded):
Zumdahl 4.83, 4.85, 4.107, 4.119, 5.21, 5.35, 5.65, 5.77, 5.85, 5.141