Chemistry Straighterline Exam With 100% Correct Answers Latest Update 2024/2025 Questions and Answers

Chemistry
Straighterline Exam
With 100% Correct
Answers
Latest Update
Questions and Answers



CHEMISTRY STRAIGHTERLINE EXAM

,An endothermic reaction causes the surroundings to:
A. warm up
B. become acidic
C. condense
D. decrease in temperature
E. release CO2 - Correct Answer-D

An exothermic reaction causes the surroundings to:
A. warm up
B. become acidic
C. expand
D. decrease its temperature
E. release CO2 - Correct Answer-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 Answer-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 Answer-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 Answer-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 Answer-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 Answer-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 Answer-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 Answer-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 Answer-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 Answer-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 Answer-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 Answer-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.
A. 154 kJ B. 44.5 kJ C. 22.5 kJ D. ─22.5 kJ E. ─56.2 kJ - Correct Answer-E

A 0.1326 g sample of magnesium was burned in an oxygen bomb calorimeter. The
Htotal heat capacity of the calorimeter plus water was 5760 J/oC. If the temperature rise

, of the calorimeter with water was 0.570oC, calculate the enthalpy of combustion of
magnesium.
Mg(s) + 1/2O2(g) MgO(s)
A. ─3280 kJ/mol B. ─24.8 kJ/mol C. 435 kJ/mol
D. 106 kJ/mol E. ─602 kJ/mol - Correct Answer-E

Which one of the following reactions occurring at 25oC does the symbol ΔHof[H2SO4(l)]
refer to?
A. 2H(g) + S(g) + 4O(g) H2SO4(l)
B. H2(g) + S(g) + 2O2(g) H2SO4(l)
C. H2SO4(l) H2(g) + S(s) + 2O2(g)
D. H2SO4(l) 2H(g) + S(s) + 4O(g)
E. H2(g) + S(s) + 2O2(g) H2SO4(l) - Correct Answer-E

Which one of the following reactions occurring at 25oC does the symbol ΔHof[HNO3(l)]
refer to?
A. H(g) + N(g) + O3(g) HNO3(l)
B. 1/2H2(g) + 1/2N2(g) + 3/2O2(g) HNO3(l)
C. HNO3(l) 1/2H2(g) + 1/2N2(g) + 3/2O2(g)
D. HNO3(l) H(g) + N(g) + 3O(g)
E. H2(g) + N2(g) + O3(g) HNO3(l) - Correct Answer-B

When 0.56 g of Na(s) react with excess F2(g) to form NaF(s) at standard state
conditions, 13.8 kJ of heat
are evolved. What is the standard enthalpy of formation (ΔHof) of NaF(s)?
A. 24.8 kJ/mol B. +570 kJ/mol C. ─24.8 kJ/mol D. ─7.8 kJ/mol
E. ─570 kJ/mol - Correct Answer-E

Ethanol undergoes combustion according to the equation:
C2H5OH(l) + O2(g) CO2(g) + H2O(l) (Not Balanced)
The standard heat of combustion of ethanol, C2H5OH(l), is ─1366.8 kJ/mol. Given that:
ΔHof[CO2(g)] = ─393.5 kJ/mol
ΔHof[H2O(l)] = ─285.8 kJ/mol
What is the standard enthalpy of formation of ethanol?
A. 3010 kJ
B. ─687.6 kJ
C. ─277.6 kJ
D. 687.6 kJ
E. 1367 kJ - Correct Answer-C

Find the standard enthalpy of formation of ethylene, C2H4(g), given the following data:
C2H4(g) + 3O2(g) 2CO2(g) + 2H2O(l) ΔHof = ─1411 kJ
C(s) + O2(g) CO2(g) ΔHof = ─393.5 kJ
H2(g) + 1/2O2(g) H2O(l) ΔHof = ─285.8 kJ
A. 52 kJ
B. 87 kJ