The slowest chemical reaction among the options provided is "B. Milk turns sour."
Here's an explanation:
1. When milk turns sour, it is due to a chemical reaction caused by the presence of bacteria in the milk.
2. The bacteria feed on the lactose (sugar) in the milk and produce lactic acid as a byproduct.
3. This lactic acid lowers the pH of the milk, making it acidic and causing the sour taste and smell.
Comparing this to the other options:
- A. Drain cleaner fizzing up as it encounters blockages in a pipe involves a rapid chemical reaction between the cleaner and the blockage.
- C. Cake rising as it cooks in the oven involves various reactions such as leavening agents (like baking powder) producing gas to make the cake rise.
- D. Baking soda and vinegar reacting is also a relatively fast reaction where carbon dioxide gas is produced.
Therefore, out of the given options, the process of milk turning sour involves a slower chemical reaction compared to the others listed.
