HC Unit 6 Study Guide

Front

What does temperature measure?

Back

The average kinetic energy of particles.

Front

What is the formula for calculating change in energy (ΔE)?

Back

ΔE = q + w

Front

Calculate ΔE for: q = 34 J, w = −22 J.

Back

12 J

Front

What is the result of the combustion of propane?

Back

C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l) with ΔH = −2221 kJ.

Front

Is energy released as heat into the surroundings or absorbed by the system during the combustion of propane?

Back

Released as heat into the surroundings.

Front

Why does the quality of energy decrease when we use it?

Back

Because energy is lost to the surroundings as heat.

Front

How much energy is released as heat when 2 mol of propane are burned in excess oxygen?

Back

-4442 kJ.

Front

What is the significance of ΔH in a chemical reaction?

Back

ΔH indicates the heat change during a reaction, with negative values indicating exothermic reactions.

Front

Define exothermic reaction.

Back

A reaction that releases energy in the form of heat.

Front

Define endothermic reaction.

Back

A reaction that absorbs energy from its surroundings.