Module 14 Thermochemistry

Question 1

What letter is used to represent heat?

Answer 1

q

Question 2

The average kinetic energy of the particles in a substance.

Answer 2

temperature

Question 3

What do we call the energy “locked up” in chemical bonds?

Answer 3

chemical potential energy

Question 4

Σ in math and science means …

Answer 4

summation

Question 5

How much heat is released by 25.0 g of an unknown metal, C=0.985 J/g°C, when ΔT is 30.0°C?

Answer 5

739 J

Question 6

What is thermochemistry?

Answer 6

The study of energy changes during chemical and physical processes.

Question 7

The total kinetic energy of all of the particles in a substance.

Answer 7

heat

Question 8

Ideally, when two objects of different temperatures come in contact, which of the following statements is incorrect?
-heat flows from a warmer object to a cooler one
-heat is transferred because of a temperature difference
-energy lost by one object must be equal to energy gained by another object
-heat is transferred from an object until none is left

Answer 8

heat is transferred from an object until none is left

Question 9

In an endothermic process…..

Answer 9

q is positive

Question 10

If it takes 525.2 kJ to melt a solid, how much heat must be lost to freeze the liquid?

Answer 10

-525.2 kJ

Question 11

True or False: 1000 Calories = 1 kilocalorie

Answer 11

False (supposed to be 1000 calories [lower case])

Question 12

What is the ΔT of a substance if m = 75.0g, C= 0.395 J/goC, and heat absorbed equals 8,530 J?

Answer 12

288°C

Question 13

Heat flow can be measured in……
-calories
-kilocalories
-Calories
-all of these are correct

Answer 13

all of these are correct

Question 14

One calorie is equal to …..
-0.001 Calorie
-4.184 Joules
-1.484 Joules
-Two of these are correct.

Answer 14

Two of these are correct. (4.184 Joules and 0.001 Calorie)

Question 15

At constant pressure, we can equate ______ with heat.

Answer 15

enthalpy

Question 16

The specific heat (capacity) of a substance ……

Answer 16

is the heat needed to raise 1 gram of the substance 1°C

Question 17

How much energy is given off when 160.5 g of CH4 freezes? ΔHfus=0.94 kJ/mol; ΔHvap= 8.2 kJ/mol

Answer 17

• 9.4 kJ

Question 18

A process that gives off heat is called….

Answer 18

exothermic

Question 19

The amount of heat released by the complete burning of one mole of a substance is ….

Answer 19

the heat of combustion.

Question 20

A device that measures heat absorbed or released during a chemical or physical process is called a ..

Answer 20

calorimeter