Question

You are supplied with five solutions: A, B, C, D and E with pH values as follows: A = 1.8, B = 7, C = 8.5, D = 13, and E = 5

Classify these solutions as neutral, slightly or strongly acidic and slightly or strongly alkaline.

Which solution would be most likely to liberate hydrogen with:

1. magnesium powder,
2. powdered zinc metal?

Give a word equation for each reaction.

Answer 1

A = Strongly acidic
B = Neutral
C = Slightly alkaline
D = Strongly alkaline
E = Slightly acidic

1. Solution (A) with magnesium powder would liberate hydrogen.
   \[\ce{Magnesium + Acid -> Magnesium salt + Hydrogen}\]

2. Solution (A) would liberate hydrogen with powdered zinc metal.
   \[\ce{Zinc + Acid -> Zinc salt + Hydrogen}\]