Arrange the following alkenes in order of increasing reactivity towards anionic polymerization. `H_2C=CHCH_(3), H_(2)C=CF_(2), H_(2)C=CHCN,H_(2)C=CHC_(6)H_(5)`

Explanation

To determine the order of increasing reactivity of the given alkenes towards anionic polymerization, we need to analyze the stability of the carbanions that would form during the polymerization process. The more stable the carbanion, the more reactive the alkene will be.

### Step-by-Step Solution:

1. **Identify the Alkenes**: The alkenes given are:
- \( H_2C=CHCH_3 \) (Propene)
- \( H_2C=CF_2 \) (Difluoroethylene)
- \( H_2C=CHCN \) (Acrylonitrile)
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