Chemistry Thermochemistry

heat capacity

the amount of heat required to raise the
temperature of 1 gram of a substance 1

law of conservation of energy

In any chemical or physical process, energy is
neither created nor destroyed.

heat of reaction

the amount of heat required to change the
temperature of an object by exactly 1C

energy

the capacity to do work or to supply hea

calorimeter

a device used to measure the amount of heat
absorbed or released during chemical o

specific heat

the amount of heat required to raise the
temperature of 1 gram of a substance 1C

heat

energy that always flows from a warmer object
to a cooler object

standard heat of formation

the change in enthalpy that accompanies the
formation of 1 mole of a compound from its
elements, with all substances in their standard
states at 25C

calorie

the quantity of heat that raises the temperature
of 1 g of pure water 1

exothermic process

the heat absorbed or released by a chemical
reaction

The SI unit of energy is

joule

How many calories are required to raise the temperature of 75.0 g of
water from 20C to 50C?

2250 cal

If 1 Calorie 4.18 kJ, how many kJ of energy can be released by an
apple containing 125 Cal

522 k

The temperature of a 6.0-g sample of glass changed from 20C to 45C
when it absorbed 550 J of heat. What is the specific heat of this glass
sample?

3.7 J/gp

The enthalpy of a system is the same as its

heat content

When your body is warmed by an electric blanket during the winter,
this process is said to be

endothermic

A student mixes two water solutions with an initial temperature of
25.0C to form a final solution with a mass of 65.0 g at 30.0C. What is
the heat change, in kJ, for this reaction

c. 1.36 k

Given the equation 2Mg(s) O2
(g) y 2MgO(s) 72.3 kJ, which of the
following is true?

H 72.3 kJ

Given the equation in question 18, how much heat is involved in the
production of 5.0 mol of MgO?

180 kj

Given the equation Si(s) 2Cl2
(g) y SiCl2
(g) y SiCl2
(l) 687 kJ, how
much heat is produced when 106 g of Cl2
react?

513 kJ

Which of the following statements is true?

b. Hfus - Hsolid

How much heat, in kJ, is required to melt 54.0 g of ice at 0C into water
at 0C if Hfus
for water 6.01 kJ/mol?

18.0 kJ

How much heat is required to convert 9.00 g of water at 100C into
steam at 100C, if Hvap
for water 40.7 kJ/mol?

20.4 kJ

If the molar heat of solution of NH4NO3
is 25.7 kJ/mol, how much heat
(in kJ) would be required to dissolve 20.0 g of NH4NO3
in water?

6.43 k

Calculate the enthalpy change, H in kJ, for the reaction

+ 279.9 k

If 22.0 mL of water containing 0.030 mol of HCl is mixed with 38.0 mL of water
containing 0.030 mol of NaOH in a calorimeter such that the initial temperature
of each solution was 27.0C and the final temperature of the mixture is 35.0C,
how much heat (in

-2.0 KJ