(Aldol, benzoin, +I, -I, decreases, increases, cyanohydrin, lactic acid, tartaric acid, yellow, white, acetone, penta-3-one, `PCl_(3)`, PCl, benzal chloride, methanol, propanoic acid, ethanol, KOH, KCN, `alpha`-hydrogen atoms, no `alpha`-hydrogens, Cannizzaro's, absence, presence)
Acetaldehyde reacts with HCN to give ........... which on hydrolysis gives ......

Explanation

To solve the question, we need to understand the reaction of acetaldehyde with hydrogen cyanide (HCN) and the subsequent hydrolysis product.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactant is acetaldehyde, which has the chemical formula CH₃CHO.

2. **Reaction with Hydrogen Cyanide**:
...