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(1) Chapter 12 Question 2 - Algorithmic Part A How many kJ of heat are needed to

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Question

(1) Chapter 12 Question 2 - Algorithmic

Part A

How many kJ of heat are needed to completely vaporize 43.2 g of H2O? The heat of vaporization for water at the boiling point is 40.6 kJ/mole.

How many kJ of heat are needed to completely vaporize 43.2 g of H2O? The heat of vaporization for water at the boiling point is 40.6 kJ/mole.

(2) Chapter 12 Question 3 - Algorithmic

Part A

A 250 gram sample of water at the boiling point had 24.0 kJ of heat added. How many grams of water were vaporized? Heat of vaporization for water is 40.6 kJ/mole.

A 250 gram sample of water at the boiling point had 24.0 kJ of heat added. How many grams of water were vaporized? Heat of vaporization for water is 40.6 kJ/mole.

(3)

Chapter 12 Question 21 - True/False

Part A

Water has a heat of vaporization of 44.0 kJ/mol while the chemical diethyl ether has a heat of vaporization of 27.1 kJ/mol. This shows that one mole of water would vaporize more easily than would one mole of diethyl ether.

Water has a heat of vaporization of 44.0 kJ/mol while the chemical diethyl ether has a heat of vaporization of 27.1 kJ/mol. This shows that one mole of water would vaporize more easily than would one mole of diethyl ether.

(4)

Exercise 11.97

Part A

How many grams of calcium are consumed when 160.4 mL of oxygen gas, measured at STP, reacts with calcium according to the following reaction?
2Ca(s)+O2(g)2CaO(s)

(5)

Exercise 11.79

A gas mixture contains 74% nitrogen and 26% oxygen.

Part A

If the total pressure is 1.18 atm what are the partial pressures of each component?

Express your answers using TWO significant figures. Enter your answers numerically separated by a comma.

a. 97.4 b. 2.26 c.16.9 d. 43.2 e. none of the above

Explanation / Answer

1)
mass of H2O = 43.2 g
molar mass of H2O = 18 g/mol

number of moles of H2O,
n = mass / molar mass
= 43.2/18
= 2.4 mol

Heat required = Hvap * mol
= 40.6 KJ/mol* 2.4 mol
= 97.44 KJ
Answer: a

I am allowed to answer only 1 question at a time