Chemistry Straighterline questions with correct answers

Chemistry Straighterline questions with
correct answers

An endothermic reaction causes the surroundings to:

A. warm up

B. become acidic

C. condense

D. decrease in temperature

E. release CO2 - CORRECT ANSWERS ✔✔D



An exothermic reaction causes the surroundings to:

A. warm up

B. become acidic

C. expand

D. decrease its temperature

E. release CO2 - CORRECT ANSWERS ✔✔A



Copper metal has a specific heat of 0.385 J/g•oC and has a melting point of
1083oC.

calculate the amount of heat required to raise the temperature of 22.8 g of Cu
from 20.0oC to 875oC.

A. 1.97 10 ─ 5 J

B. 1.0 10 ─ 2 J

,C. 329 J

D. 7.51 kJ

E. 10.5 kJ - CORRECT ANSWERS ✔✔D



Calculate the amount of heat necessary to raise the temperature of 12.0 kg of
water from 15.4oC to 93.0oC.

A. 0.027 kJ B. 324 kJ C. 389 kJ D. 931 kJ

E. 3890 kJ - CORRECT ANSWERS ✔✔E



How much heat is required to raise the temperature of 1500 g of water from
25oC

to 52oC?

A. 1500 kJ B. 169 kJ C. 6.27 kJ D. 40.5 J E. 40.5 kJ - CORRECT ANSWERS
✔✔B



How many degrees of temperature rise will occur when a 25.0 g block of
aluminum absorbs 10 kJ of heat? The specific heat of Al is 0.900 J/g•oC.

A. 0.44oC B. 22.5oC C. 225oC D. 360oC E. 444oC - CORRECT ANSWERS ✔✔E



If 325 g of water at 4.2oC absorbs 12.28 kJ, then what is the final temperature
of the water?

A. 4.21oC B. 4.8oC C. 9.0oC D. 13.2oC E. 2938oC - CORRECT ANSWERS
✔✔D

,A glass containing 200 g of H2O at 20oC was placed into a refrigerator. The
water loses 11.7 kJ as it cools to a constant temperature. What is its new
temperature?

A. 0.013oC B. 4oC C. 6oC D. 14oC E. 34oC - CORRECT ANSWERS ✔✔C



A piece of copper with a mass of 218 g has a heat capacity of 83.9 J/oC. What is
the specific heat of copper?

A. 0.385 J/g•oC B. 1.83 ´ 104 J/g•oC C. 2.60 J/g•oC D. 1.32 J/g•oC

E. 24.5 J/g•oC - CORRECT ANSWERS ✔✔A



The specific heat of gold is 0.129 J/g•oC. What is the molar heat capacity of
gold (unit is J/mol•oC)?

A. 0.039 J/mol•oC

B. 0.129 J/mol•oC

C. 25.4 J/mol•oC

D. 39.0 kJ/mol•oC

E. 197 J/mol•oC - CORRECT ANSWERS ✔✔C



When 0.7521 g of benzoic acid was burned in a calorimeter containing 1000 g
of water, a temperature rise of 3.60oC was observed. What is the heat capacity
of the bomb calorimeter, excluding water? The heat of combustion of benzoic
acid is ─26.42 kJ/g.

A. 15.87 kJ/oC

B. 4.18 kJ/oC

C. 5.52 kJ/oC

, D. 1.34 kJ/oC

E. 752.1 kJ/oC - CORRECT ANSWERS ✔✔D



Naphthalene combustion can be used to determine the heat capacity of a bomb
calorimeter. The heat of combustion of naphthalene is 40.1 kJ/g. When 0.8210
g of naphthalene was combusted in a calorimeter containing 1000 g of water a
temperature rise of 4.21oC was observed. What is the heat capacity of the
bomb calorimeter excluding the water?

A. 32.9 kJ/oC

B. 7.8 kJ/oC

C. 1.76 kJ/oC

D. 1.76 kJ/oC

E. 15.3 kJ/oC - CORRECT ANSWERS ✔✔C



Which of the following processes is endothermic?

a. O2(g) + 2H2(g) 2H2O(g)

b. H2O(g) H2O(l)

c. 3O2(g) + 2CH3OH(g) 2CO2(g) + 2H2O(g)

d. H2O(s) H2O(l) - CORRECT ANSWERS ✔✔D



A 100 mL sample of 0.200 M aqueous hydrochloric acid is added to 100 mL of
0.200 M aqueous ammonia in a calorimeter whose heat capacity is 480 J K ─ 1.
The following reaction occurs when the two solutions are mixed.

HCl(aq) + NH3(aq) NH4Cl(aq)

The temperature increase is 2.34oC. Calculate ΔH per mole of HCl neutralized.