Home Chapter 5: Thermochemistry Quiz 1

# Quiz 1

This activity contains 12 questions.

 Substance Hf° (kJ/mol) SO2(g) -297 SO3(g) -396 SO2Cl2(g) -364 H2SO4(l) -814 H2O(l) -286

Determine the value of in kJ for the following reaction:
2SO2(g) + O2(g) --> 2SO3(g)

 -99 -198 99 198

Calculate H° for the following reaction, using the given enthalpies of formation.

2NO(g) + O2(g) --> 2NO2(g)

Hf[NO(g)] = 90.25 kJ mol-1

Hf[NO2(g)] = 33.18 kJ mol-1

 -114.5 kJ +57.07 kJ +114.5 kJ -57.07 kJ

Consider the combustion reaction of ethane gas, C2H6(g):

C2H6(g) + 7/2O2(g) --> 2CO2(g) + 3H2O(g) H = -1430 kJ

What is the enthalpy change for the reverse reaction if whole-number coefficients are used?

 -2860 kJ +715 kJ +2860 kJ -1430 kJ +1430 kJ

Consider the reaction

Pb2+(aq) + 2Cl-(aq) --> PbCl2(s) H = -22.53 kJ/mol

Calculate H when 0.230 mol of PbCl2(s) is dissolved in water.

 -5.18 kJ 22.5 kJ 5.18 kJ -22.5 kJ

From the following heats of reaction,

2C (graphite) + H2 (g) --> C2H2 (g) H = 227 kJ

6C (graphite) + 3H2 (g) --> C6H6 (l) H = 49 kJ

calculate the heat for the reaction

3C2H2 (g) --> C6H6 (l)

 632 kJ 26.7 kJ 178 kJ -26.7 kJ -178 kJ -632 kJ

## How many kJ of heat must be removed from 1000. g of water (heat capacity of 4.184 J g-1 K-1) to lower the temperature from 18.0°C to 12.0°C?

 2.5 x 10-2 kJ 25 kJ 4.2 kJ 1.4 kJ

## How much heat in kJ is required to raise the temperature of 125 g H2O from 2.2°C to 48.6°C? (The specific heat of water is 4.18 J g-1 °C-1.)

 1.39 kJ 48.4 kJ 24.2 kJ 436 kJ

## Of the substances below, which one has the highest fuel value?

 bituminous coal natural gas gasoline charcoal wood

## The heat of combustion of fructose, C6H12O6(s), is -2812 kJ/mol. Using the information in Table 5.3, calculate H°f for fructose.

 -999.8 kJ/mol -1264 kJ/mol -210.3 kJ/mol 210.3 kJ/mol 1264 kJ/mol +2133 kJ/mol

Use the H values for equations 1 and 2 to determine the value of H for equation 3.
(1) 2NO --> N2 + O2 H = -180 kJ
(2) 2NO + O2 --> 2NO2 H = -112 kJ
(3) N2 + 2O2 --> 2NO2 H = ?

 68 -292 292 -68

Use the following thermochemical equations

C2H5OH (l) + 3O2(g) --> 2CO2 (g) + 3H2O (l) H° = -1367 kJ

H2(g) + 1/2 O2(g) --> H2O(l) H° = -286 kJ

C (graphite) + O2(g) --> CO2(g) H° = -394 kJ

to calculate the enthalpy change for the following reaction:

2C (g) + 3H2 (g) + 1/2O2 (g) --> C2H5OH (l) H° = ?

 +687 kJ +680 kJ +279 kJ +2047 kJ -279 kJ

## Which of the following is not a state function?

 The energy expended in lifting a book down off of a shelf and setting it on a desk The change in potential energy involved in carrying a pail of water up a hill the heat content of a cold can of soda at 10°C the electrical charge contained in a fresh flashlight battery