Homework Answers

Example:

Decomposition of mercuric oxide HgO to mercury Hg and oxygen O2 gas, requires

87.1kJ of heat,

HgO(s)  Hg(l) + O2(g) ΔH = + 87.1kJ (needs to absorb energy)

1. Combustion of hexane, C6H12 to carbon dioxide gas and water, releases 3923.9kJ

of heat.

2. Reaction between solid phosphorous, P4 and oxygen gas, produces P3O6 and

1640.1kJ of heat.

3. One mole ammonium nitrate (NH4NO3) dissolves in water to produce aqueous

ammonium ions and nitrate ions accompanied by the absorption of 28.1 kJ of heat.

4. Formation of carbon dioxide gas from carbon (graphite) and oxygen yields 393.5

kJ of heat.

Please solve it like this

1. Answer

2. Answer

3. Answer

4. Answer

1.) Calculate ΔE if 120kJ of heat energy is absorbed by the system and 40kJ of work

is done on the surroundings.

2.) Find ΔE when a gas absorbs 30kJ of hear and has 15kJ of work done on it.

3.) If the internal energy of a reaction is 480J and the system absorbs 839J of heat

from it’s surrounds,

a. Find the amount of work.

b. Is the work done by the system or work is done on the system? Explain.

Please solve it like this

1. SOLUTION

2. SOLUTION

3.A.SOLUTION

B. EXPLAIN

2. A solution was produced by dissolving 3.75 g of a nonvolatile solute in 95g of

acetone. The boiling point of pure acetone was observed to be 55.95 ºC, while the boiling

point of the solution was 56.50ºC. If the boiling point for acetone is 1.71ºC/m, what is the

approximate molar mass of solute?

Step 1: First compute the molality of the boiling point equation.

Step 2. Then, from the definition of molality, compute the number of moles

solute, n(solute), in the sample.

Step 3. Solve for the molar mass.

Please solve it like this

STEP1: SOLUTION

STEP2: SOLUTION

STEP3: SOLUTION

THANK YOUUU

1. A solution containing 4.50 g of a non electrolyte (i=1) dissolved in 125 g of water

freezes at -0.372ºC. Calculate the molar mass of the solute.

Step 1: First compute the molality of the freezing point equation.

Step 2. Then, from the definition of molality, compute the number of moles

solute, n(solute), in the sample.

Step 3. Solve for the molar mass.

Please solve it like this

STEP1: SOLUTION

STEP2:; SOLUTION

STEP3: SOLUTION