Practice Exothermic Reaction in Chemistry
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
A chemical reaction that releases energy (usually as heat or light) to the surroundings, resulting in an increase in surrounding temperature and a negative enthalpy change (\Delta H < 0).
The reaction gives off heat—you can feel the surroundings get warmer as it proceeds.
Example 1
easyExplain why burning methane (\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}) is an exothermic reaction.
Example 2
mediumA reaction releases 890 kJ of heat per mole of methane burned. If 3.2 g of \text{CH}_4 is burned (M = 16\,\text{g/mol}), how much heat is released?
Example 3
easyA hand warmer packet heats up when activated. Is this an exothermic or endothermic process? Explain.
Example 4
easyA reaction mixture causes the beaker and surrounding air to become warmer. Is the reaction exothermic or endothermic? Explain.