Question 1

The standard state of carbon is ________.

Accepted Answer

The answer of The standard state of carbon is ________....

Question 2

How much energy is required to decompose 765 g of PCl3 according to the reaction below? The molar mass of PCl3 is 137.32 g $\mathrm { mol } ^ { - 1 }$ and may be useful. 4PCl3(g)? P4(s)+ 6Cl2(g) 
DrH° = +1207 kJ

Accepted Answer

A) 2.31 × 103 kJ 
B) 4.33 × 103 kJ 
C) 6.72 × 103 kJ 
D) 1.68 × 103 kJ 
E) 5.95 × 103 kJ 
A) 2.31 × 103 kJ 
B) 4.33 × 103 kJ 
C) 6.72 × 103 kJ 
D) 1.68 × 103 kJ 
E) 5.95 × 103 kJ

Question 3

8.000 moles of H2(g)reacts with 4.000 mol of O2(g)to form 8.000 mol of H2O(l)at 25 °C and a constant pressure of 1.0133 bar.If 546.4 kJ of heat are released during this reaction,and PΔV is equal to -29.60 kJ,then

Accepted Answer

A) ΔH° = +546.4 kJ and ΔU° = +576.06 kJ. 
B) ΔH° = +546.4 kJ and ΔU° = +516.8 kJ. 
C) ΔH° = -546.4 kJ and ΔU° = -516.8 kJ. 
D) ΔH° = -546.4 kJ and ΔU° = -576.0 kJ. 
A) ΔH° = +546.4 kJ and ΔU° = +576.06 kJ. 
B) ΔH° = +546.4 kJ and ΔU° = +516.8 kJ. 
C) ΔH° = -546.4 kJ and ΔU° = -516.8 kJ. 
D) ΔH° = -546.4 kJ and ΔU° = -576.0 kJ.

Question 4

Calculate the heat transfer (J)when 3.15 g of platinum (specific heat capacity = 0.133 J g-1 °C-1)at 86.1 °C cools to room temperature,24.3 °C.

Accepted Answer

A) -26 J 
B) 26 J 
C) -60 J 
D) 60 J 
E) -17 J 
A) -26 J 
B) 26 J 
C) -60 J 
D) 60 J 
E) -17 J

Question 5

A 6.55 g sample of aniline (C6H5NH2,molar mass = 93.13 g $\mathrm { mol } ^ { - 1 }$ )was combusted in a bomb calorimeter with a heat capacity of 14.25 kJ ${ } ^ { \circ } \mathrm { C } ^ { - 1 }$ .If the initial temperature was 32.9 °C,use the information below to determine the value of the final temperature of the calorimeter. 4C6H5NH2(l)+ 35O2(g)? 24CO2(g)+ 14H2O(g)+ 4NO2(g) 
$\mathrm { D } _ { \mathrm { r } } U ^ { \circ }$ = -1.28 × 104 kJ $\mathrm { mol } ^ { - 1 }$

Accepted Answer

A) 257 °C 
B) 46.6 °C 
C) 96.1 °C 
D) 41.9 °C 
E) 931 °C 
A) 257 °C 
B) 46.6 °C 
C) 96.1 °C 
D) 41.9 °C 
E) 931 °C

Question 6

Calculate the heat transfer,in kJ,when 1.287 kg of chicken breast (specific heat capacity = 1.82 J g-1 °C-1)is removed from a freezer at -17.3 °C and allowed to warm up to 0.00 °C.You need not be concerned about melting of ice or any other phase changes.

Accepted Answer

A) -0.0405 kJ 
B) 0.0405 kJ 
C) -40.5 kJ 
D) 40.5 kJ 
E) 8.65 kJ 
A) -0.0405 kJ 
B) 0.0405 kJ 
C) -40.5 kJ 
D) 40.5 kJ 
E) 8.65 kJ

Question 7

A student is preparing to perform a series of calorimetry experiments.She first wishes to determine the calorimeter constant (Ccal)for her coffee cup calorimeter.She pours a 50.0 mL sample of water at 345 K into the calorimeter containing a 50.0 mL sample of water at 298 K.She carefully records the final temperature of the water as 317 K.What is the value of Ccal for the calorimeter?

Accepted Answer

A) 19 J K-1 
B) 28 J K-1 
C) 99 J K-1 
D) 21 J K-1 
E) 76 J K-1 
A) 19 J K-1 
B) 28 J K-1 
C) 99 J K-1 
D) 21 J K-1 
E) 76 J K-1

Question 8

Which of the following processes is exothermic?

Accepted Answer

A) the ionization of a lithium atom 
B) the breaking of a Cl-Cl bond 
C) the sublimation of dry ice (CO2(s)) 
D) the reaction associated with $D _ { f }$ H° for an ionic compound 
A) the ionization of a lithium atom 
B) the breaking of a Cl-Cl bond 
C) the sublimation of dry ice (CO2(s)) 
D) the reaction associated with $D _ { f }$ H° for an ionic compound

Question 9

What is the enthalpy change (in kJ)of a chemical reaction that raises the temperature of 250.0 mL of solution having a density of 1.25 g $\mathrm { mL } ^ { - 1 }$ by 10.2 °C? (The specific heat of the solution is 3.733 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .)

Accepted Answer

A) -7.43 kJ 
B) -12.51 kJ 
C) 8.20 kJ 
D) -11.9 kJ 
E) 6.51 kJ 
A) -7.43 kJ 
B) -12.51 kJ 
C) 8.20 kJ 
D) -11.9 kJ 
E) 6.51 kJ

Question 10

Calculate the amount (mass)of acetaldehyde (C2H4O,molar mass = 44.0526 g mol-1)that causes a bomb calorimeter with a heat capacity of 12.91 kJ °C-1 to have a temperature increase from 27.8 °C to 41.7 °C.The DrU for the combustion of acetaldehyde is -1166.9 kJ mol-1.

Accepted Answer

A) 6.77 g 
B) 8.67 g 
C) 4.29 g 
D) 7.30 g 
E) 5.55 g 
A) 6.77 g 
B) 8.67 g 
C) 4.29 g 
D) 7.30 g 
E) 5.55 g

Question 11

A 35.6 g sample of ethanol (C2H5OH)is burned in a bomb calorimeter according to the following reaction.If the temperature rose from 35.0 °C to 76.0°C and the heat capacity of the calorimeter is 23.3 kJ ${ } ^ { \circ } \mathrm { C } ^ { - 1 }$ ,what is the value of $\mathrm { D } _ { \mathrm { r } } U ^ { \circ }$? The molar mass of ethanol is 46.07 g $\mathrm { mol } ^ { - 1 }$ . C2H5OH(l)+ 3O2(g)? 2CO2(g)+ 3H2O(g) $\mathrm { D } _ { \mathrm { r } } U ^ { \circ }$= ?

Accepted Answer

A) -1.24 × 103 kJ mol-1 
B) +1.24 × 103 kJ mol-1 
C) -8.09 × 103 kJ mol-1 
D) -9.55 × 103 kJ mol-1 
E) +9.55 × 103 kJ mol-1 
A) -1.24 × 103 kJ mol-1 
B) +1.24 × 103 kJ mol-1 
C) -8.09 × 103 kJ mol-1 
D) -9.55 × 103 kJ mol-1 
E) +9.55 × 103 kJ mol-1

Question 12

Identify the unit of heat capacity.

Accepted Answer

A) J °C-1 
B) J g-1 °C-1 
C) J mol-1 °C-1 
D) g °C-1 
E) mol °C-1 
A) J °C-1 
B) J g-1 °C-1 
C) J mol-1 °C-1 
D) g °C-1 
E) mol °C-1

Question 13

For $\Delta$sysU to always be -,what must be true?

Accepted Answer

A) q = w 
B) +q > -w 
C) +w > -q 
D) -w > +q 
A) q = w 
B) +q > -w 
C) +w > -q 
D) -w > +q

Question 14

Calculate the final temperature of a 38.1 g piece of graphitic carbon,originally at 100.0 °C,placed inside a coffee cup calorimeter containing 68.0 mL of water at 24.6 °C.The specific heat capacity of water is 4.184 J g-1 °C-1,the specific heat capacity of graphitic carbon is 0.709 J g-1 °C-1,and the density of water is 1.00 g mL-1.

Accepted Answer

A) 14.7 °C 
B) 26.8 °C 
C) 31.1 °C 
D) 28.6 °C 
E) 34.0 °C 
A) 14.7 °C 
B) 26.8 °C 
C) 31.1 °C 
D) 28.6 °C 
E) 34.0 °C

Question 15

Calculate the final temperature of 6.84 g of praseodymium (specific heat capacity = 0.193 J g-1 °C-1)initially at 26.8 °C that releases 11.3 J of energy into the surroundings.

Accepted Answer

A) 14.3°C 
B) 18.2 °C 
C) 21.6 °C 
D) 23.8 °C 
E) 8.17 °C 
A) 14.3°C 
B) 18.2 °C 
C) 21.6 °C 
D) 23.8 °C 
E) 8.17 °C

Question 16

Which of the following is TRUE if $\Delta$sysU = -95 J?

Accepted Answer

A) The system is gaining 95 J,while the surroundings are losing 95 J. 
B) The system is losing 95 J,while the surroundings are gaining 95 J. 
C) Both the system and the surroundings are gaining 95 J. 
D) Both the system and the surroundings are losing 95 J. 
E) None of the above are true. 
A) The system is gaining 95 J,while the surroundings are losing 95 J. 
B) The system is losing 95 J,while the surroundings are gaining 95 J. 
C) Both the system and the surroundings are gaining 95 J. 
D) Both the system and the surroundings are losing 95 J. 
E) None of the above are true.

Question 17

Use the DfH° information provided to calculate DrH° for the following: $$\begin{array} { l r r l } 
& \mathrm { D } _ { \mathrm { f } } H ^ { \circ } ( \mathrm { kJ } \mathrm { mol } - 1 ) & \mathrm { SO } _ { 2 } \mathrm { Cl } _ { 2 } ( g ) + 2 \mathrm { H } _ { 2 } \mathrm { O } ( l ) \rightarrow 2 \mathrm { HCl } ( g ) + \mathrm { H } _ { 2 } \mathrm { SO } ( l ) \quad \mathrm { D } _ { \mathrm { r } } H ^ { \circ } = ? \
\mathrm { SO } _ { 2 } \mathrm { Cl } _ { 2 } ( g ) & - 364 & & \
\mathrm { H } _ { 2 } \mathrm { O } ( l ) & - 286 & \
\mathrm { HCl } ( g ) & 92 & \
\mathrm { H } _ { 2 } \mathrm { SO } _ { 4 } ( l ) & - 814 &
\end{array}$$

Accepted Answer

A) -256 kJ mol-1 
B) +161 kJ mol-1 
C) -62 kJ mol-1 
D) +800.kJ mol-1 
E) -422 kJ mol-1 
A) -256 kJ mol-1 
B) +161 kJ mol-1 
C) -62 kJ mol-1 
D) +800.kJ mol-1 
E) -422 kJ mol-1

Question 18

Define specific heat capacity.

Accepted Answer

A) the quantity of heat required to raise the temperature of 1 mol of a substance by 1 °C 
B) the quantity of heat required to change a system's temperature by 1 °C 
C) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °C 
D) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °F 
E) the quantity of heat required to raise the temperature of 1 L of a substance by 1 °C 
A) the quantity of heat required to raise the temperature of 1 mol of a substance by 1 °C 
B) the quantity of heat required to change a system's temperature by 1 °C 
C) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °C 
D) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °F 
E) the quantity of heat required to raise the temperature of 1 L of a substance by 1 °C

Question 19

Define heat capacity.

Accepted Answer

A) the quantity of heat required to raise the temperature of 1 mol of a substance by 1 °C 
B) the quantity of heat required to change a system's temperature by 1 °C 
C) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °C 
D) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °F 
E) the quantity of heat required to raise the temperature of 1 L of a substance by 1 °C 
A) the quantity of heat required to raise the temperature of 1 mol of a substance by 1 °C 
B) the quantity of heat required to change a system's temperature by 1 °C 
C) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °C 
D) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °F 
E) the quantity of heat required to raise the temperature of 1 L of a substance by 1 °C

Question 20

Calculate the kinetic energy of a 150 g baseball moving at a speed of 39.m $s ^ { - 1 }$ (87 mph).

Accepted Answer

A) 5.8 J 
B) 1.1 × 102 J 
C) 5.8 × 103 J 
D) 1.1 × 105 J 
A) 5.8 J 
B) 1.1 × 102 J 
C) 5.8 × 103 J 
D) 1.1 × 105 J

Exam 6: Thermochemistry

The standard state of carbon is ________.

How much energy is required to decompose 765 g of PCl3 according to the reaction below? The molar mass of PCl3 is 137.32 g mol−1\mathrm { mol } ^ { - 1 }mol−1 and may be useful. 4PCl3(g)? P4(s)+ 6Cl2(g) DrH° = +1207 kJ

8.000 moles of H2(g)reacts with 4.000 mol of O2(g)to form 8.000 mol of H2O(l)at 25 °C and a constant pressure of 1.0133 bar.If 546.4 kJ of heat are released during this reaction,and PΔV is equal to -29.60 kJ,then

Calculate the heat transfer (J)when 3.15 g of platinum (specific heat capacity = 0.133 J g-1 °C-1)at 86.1 °C cools to room temperature,24.3 °C.

Calculate the heat transfer,in kJ,when 1.287 kg of chicken breast (specific heat capacity = 1.82 J g-1 °C-1)is removed from a freezer at -17.3 °C and allowed to warm up to 0.00 °C.You need not be concerned about melting of ice or any other phase changes.

Which of the following processes is exothermic?

What is the enthalpy change (in kJ)of a chemical reaction that raises the temperature of 250.0 mL of solution having a density of 1.25 g mL−1\mathrm { mL } ^ { - 1 }mL−1 by 10.2 °C? (The specific heat of the solution is 3.733 J g−1g ^ { - 1 }g−1 K−1\mathrm { K } ^ { - 1 }K−1 .)

Calculate the amount (mass)of acetaldehyde (C2H4O,molar mass = 44.0526 g mol-1)that causes a bomb calorimeter with a heat capacity of 12.91 kJ °C-1 to have a temperature increase from 27.8 °C to 41.7 °C.The DrU for the combustion of acetaldehyde is -1166.9 kJ mol-1.

Identify the unit of heat capacity.

For Δ\DeltaΔ sysU to always be -,what must be true?

Calculate the final temperature of 6.84 g of praseodymium (specific heat capacity = 0.193 J g-1 °C-1)initially at 26.8 °C that releases 11.3 J of energy into the surroundings.

Which of the following is TRUE if Δ\DeltaΔ sysU = -95 J?

Use the DfH° information provided to calculate DrH° for the following: (-1) (g)+2(l)\rightarrow2(g)+(l)=? (g) -364 (l) -286 (g) 92 (l) -814

Define specific heat capacity.

Define heat capacity.

Calculate the kinetic energy of a 150 g baseball moving at a speed of 39.m s−1s ^ { - 1 }s−1 (87 mph).

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How much energy is required to decompose 765 g of PCl₃ according to the reaction below? The molar mass of PCl₃ is 137.32 g $\mathrm { mol } ^ { - 1 }$ and may be useful. 4PCl₃(g)? P₄(s)+ 6Cl₂(g) D_rH°= +1207 kJ

8.000 moles of H₂(g)reacts with 4.000 mol of O₂(g)to form 8.000 mol of H₂O(l)at 25 °C and a constant pressure of 1.0133 bar.If 546.4 kJ of heat are released during this reaction,and PΔV is equal to -29.60 kJ,then

Calculate the heat transfer (J)when 3.15 g of platinum (specific heat capacity = 0.133 J g^-1 °C^-1)at 86.1 °C cools to room temperature,24.3 °C.

Calculate the heat transfer,in kJ,when 1.287 kg of chicken breast (specific heat capacity = 1.82 J g^-1 °C^-1)is removed from a freezer at -17.3 °C and allowed to warm up to 0.00 °C.You need not be concerned about melting of ice or any other phase changes.

What is the enthalpy change (in kJ)of a chemical reaction that raises the temperature of 250.0 mL of solution having a density of 1.25 g $\mathrm { mL } ^ { - 1 }$ by 10.2 °C? (The specific heat of the solution is 3.733 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .)

Calculate the amount (mass)of acetaldehyde (C₂H₄O,molar mass = 44.0526 g mol^-1)that causes a bomb calorimeter with a heat capacity of 12.91 kJ °C^-1 to have a temperature increase from 27.8 °C to 41.7 °C.The D_rU for the combustion of acetaldehyde is -1166.9 kJ mol^-1.

For $\Delta$ _sysU to always be -,what must be true?

Calculate the final temperature of 6.84 g of praseodymium (specific heat capacity = 0.193 J g^-1 °C^-1)initially at 26.8 °C that releases 11.3 J of energy into the surroundings.

Which of the following is TRUE if $\Delta$ _sysU = -95 J?

Use the _DfH° information provided to calculate _DrH° for the following: (-1) (g)+2(l)\rightarrow2(g)+(l)=? (g) -364 (l) -286 (g) 92 (l) -814

Calculate the kinetic energy of a 150 g baseball moving at a speed of 39.m $s ^ { - 1 }$ (87 mph).