Does ethyl propenyl ether have any resonance structures? If so, then draw them.

10.11 mL

Explanation:

Given that :

Total volume of decolorizer = 500 mL

A common recipe is equal parts 95% ethanol and acetone.

So;

The volume of 95% ethanol in the decolorizer = 500mL/2 = 250 mL

Let represent V(ml) for the 99% of ethanol needed to make 95% of the 250 mL of ethanol;

Therefore:

V(ml) × 0.99 = 250 × 0.95

V(ml) × 0.99 = 237.5

V(ml)  = 237.5/0.99

V(ml) = 239.89 mL

Hence; the amount of water to be added to 95% of ethanol = ( 250 -  239.89 )mL = 10.11 mL