Answer:
The rate of reaction is doubled
Explanation:
The reaction between 1-iodopropane and sodium hydroxide is an SN2 reaction. This reaction takes place by a concerted mechanism and the hydroxide ion is the nucleophile.
In an SN reaction, the reaction is second order because the rate of reaction depends both on the concentration of the alkylhalide and that of the nucleophile. Hence, when the concentration of 1-iodopropane (the alkyl halide) is held constant and the concentration of hydroxide ion (the nucleophile) is doubled, the rate of reaction is doubled since;
Rate =k [1-iodopropane] [OH^-]