Q. 7.73 - An Introduction to General, Organic, and Biological Chemistry

Question

a. What is meant by the rate of a reaction?

b. Why does bread grow mold more quickly at room temperature than in the refrigerator?

Step-by-Step Solution

Answer

a. The reaction or reaction speed is the speed at which reactants are converted into products.  

b. The presence of water assists bread mould production hence mold grows best at room temperature and struggles in colder temperatures. 

Part(a) Step 1: Given information

We need to find out what is meant by the rate of a reaction.

Part(a) Step 2: Explanation

The reaction rate or reaction speed is the speed at which reactants are changed over into products. Rate of chemical reaction can also be defined as the change in the concentration of a product/reactant divided by the time interval at which this change is observed: 

 $Rate=\frac{∆concentration}{∆time}$

Part(b) Step 1: Given information

We need to find out why does bread grow mold more quickly at room temperature than in the refrigerator.

Part(b) Step 2: Explanation

Because enzymes, or proteins that control chemical reactions, function more efficiently at higher temperatures, warm temperatures promote optimal mould development. The presence of water assists bread mould production because the watery nature of this environment aids the mixing process and movement of nutrients in the bread mould. Mold grows best at room temperature and struggles in colder temperatures. Mold will grow slowly on refrigerated bread, while mould will not form at all on frozen bread.