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

Answer:

solutio A and b is correct

Answer 2

Answer:

The solution which liberates hydrogen with magnesium powder is solution A with pH $1.8$.

Therefore, option b) Solution $A$ is correct.

Explanation:

Given,

The pH of the solution A = $1.8$

The pH of the solution B = $7$

The pH of the solution C = $8.5$

The pH of the solution D = $8$

The pH of the solution E = $5$

The solution which liberates hydrogen with magnesium powder =?

Firstly, we have to classify the given solutions into acidic, basic or neutral solutions.

• The pH of the solution A = $1.8$ = strongly acidic

• The pH of the solution B = $7$ = neutral
• The pH of the solution C = $8.5$ = weakly alkaline
• The pH of the solution D = $8$ = weakly alkaline
• The pH of the solution E = $5$ = weakly acidic

As we know,

• The magnesium powder when reacts with a strong acid like $HCl$, liberates hydrogen gas.

For example: $Mg + 2HCl \rightarrow MgCl_{2} + H_{2} \uparrow$

Thus,

• When magnesium powder reacts with strong acid, it liberates hydrogen gas.

Therefore, out of the given solution, solution A with pH $1.8$ is strongly acidic.

Hence, solution A with pH $1.8$ is most likely to liberate hydrogen with magnesium powder.