Question

Experiment 5: Last week, you set up and observed an endothermic and two exothermic reactions in aqueous solution. These reactions yielded solid, aqueous, or gaseous products. This week, you will conduct two different gas-producing reactions and use the corresponding flammable products in a combustion reaction to propel a mini-rocket. In all chemical reactions, it is important to first write a balanced chemical equation to predict the relative reactant amounts needed to make the amount of desired product and achieve the desired result. It is our experimental goal this week to combine and optimize the ratios of two combustible gas reaction products, oxygen and hydrogen, to propel a pipette-bulb rocket.

1. The following reaction is an example of what type of reaction?

2H2+O2->2H2O

1. Why is a catalyst needed in the decomposition of hydrogen peroxide into oxygen gas and water.

2. True or False: Yeast was the catalyst of the decomposition of hydrogen peroxide into oxygen gas and water.

3. What experimental components hindered the launch of the pipet rockets in Experiment 5?

4. In Experiment 5, you were asked to fill up the pipet bulb with water before adding the gases. Why did you need to do this?

Answer 1

1. It is an example of condensation reaction. It is also a synthesis reaction.

2. A catalyst is needed to reduce the activation energy barrier required for the decomposition of hydrogen peroxide.

3. True. Yeast contains an enzyme catalase that helps in the breakdown of hydrogen peroxide.

4. In exothermic reactions, a large amount of heat energy is released, hence water is used to cool down the system