Nelson Chemistry Chapter 10 Quiz
Click on the correct answer
1
Which statement correctly describes the energy changes when a solid changes to a liquid at constant temperature?
The potential energy remains constant and the kinetic energy increases.
The potential energy increases and the kinetic energy remains constant.
The potential energy increases and the kinetic energy decreases.
The potential energy decreases and the kinetic energy decreases.
2
When 100 g of steam at 100
o
C change to water at 100
o
C, there is
a release of 33.5 kJ of energy
an absorption of 33.5 kJ of energy
an absorption of 226 kJ of energy
a release of 226 kJ of energy
3
The molar heat of a phase change is the amount of energy
released or absorbed when one mole of substance is changed from one phase to another.
released or absorbed when one mole of substance is formed from its elements.
needed to raise the temperature of one mole one degree Celsius.
needed to raise the temperature of one gram one degree Celsius.
4
The combustion of a 5.00 g sample of cellulose in a bomb calorimeter causes 2.35 kg of water to increase in temperature from 20.4
o
C to 24.5
o
C. What is the heat produced by this reaction?
85.9 J
8.07 kJ
19.4 kJ
40.4 kJ
5
A substance has a molar heat of combustion of -810.4 kJ/mol. When 0.285 mol of the substance is burned in a calorimeter containing 8.60 kg of water, the increase in water temperature is
0.156
o
C
6.41
o
C
7.89
o
C
12.8
o
C
6
2.00 mol of an element burned in a calorimeter raises the temperature of 200 g of water 10.0
o
C The molar heat of combustion of the element is
0.239 kJ/mol
4.18 kJ/mol
8.36 kJ/mol
16.7 kJ/mol
7
The energy change that accompanies exothermic reactions comes from
the addition of energy on the reactant side of the equation
the higher temperature readings from the products
the breaking and reforming of chemical bonds
an increase in the motion of the particles
8
Calculate the total energy change of 500 g of Al(l) solidifying from 950
o
C to 23.0
o
C. The molar enthalpy of solidification of aluminum is 10.67 kJ/mol. The specific heat capacity of Al(l) is 1.09 J/g
o
C and Al(s) is 0.897 J/g
o
C.
703 kJ
642 kJ
615 kJ
445 kJ
9
750 g of ammonium nitrate is dissolved in 650 mL of water causing the temperature of the water to drop from 25.6
o
C to 1.02
o
C. What is the molar enthalpy of ammonium nitrate?
89.3 kJ/mol
7.44 kJ/mol
7.15 kJ/mol
5.36 kJ/mol
10
The total energy of a substance is equal to
mc delta t
its heat of formation
the sum of its kinetic and potential energies
The difference between its kinetic and potential energies
11
A calorimeter and its contents have a heat capacity of 19.7 kJ/
o
C. When the temperature of the calorimeter changes from 46.2
o
C to 12.1
o
C, the energy change in the calorimeter and its contents is
238 kJ gained
672 kJ gained
672 kJ lost
910 kJ lost
12
Which of these process is exothermic?
The freezing of water
The vapourization of water
The sublimation of dry ice into gas
The boiling of liquid nitrogen