Question

You are having five solutions A, B, C, D and E with pH values as follows: A = 1.8, B = 7, C = 8.5, D = 8 and E = 5 

Which solution would be most likely to liberate hydrogen with magnesium powder? 

A. Solution A and B 

B. Solution A 

C. Solution C 

D. All of the above

Answer 1

When magnesium powder reacts with HCl, it forms magnesium chloride and liberated hydrogen gas. 

The reaction that takes place is: 

Mg + 2HCl → MgCl₂ + H₂ 

As we know that HCl is a strong acidic solution. The pH of acidic solution is less than 7. Being a strong acid, the pH of HCl is 1.8.

Hence option (B) is correct.