Question

If 10 mL of H2SO4 is mixed with 10 mL of Mg(OH)2 of the same
concentration, the resultant solution will give the following colour with
universal indicator :
(A) Red
(B) Yellow
(C) Green
(D) Blue​

Answer 1

The resultant solution will give  c) Green Colour with the Universal Indicator.

• Given, 10 mL of H2SO4 is mixed with 10mL of Mg(OH)2  of the same concentration.
• This shows number of moles of acid equals the number of moles of base here.
• Also, this is a strong acid- strong base titration.
• Reaction is:   H2SO4 + Mg(OH)2 ⇒ MgSO4 + 2H2O
• As same amount of acid is added to same amount of base, the reaction attains equivalence point and the pH of the reaction becomes 7.
• We know, the Universal Indicators absorb Green Colour radiations at   pH = 7

Answer 2

Given that,

If 10 ml  of $H_{2}S)_{4}$ is mixed with 10 ml $Mg(OH)_{2}$ of the same concentration.

We know that,

Here, The number of moles of acid equals the number of moles of base.

This is a strong acid- strong base titration.

The reaction is

$H_{2}SO_{4}+Mg(OH)_{2}\Rightarrow MgSO_{4}+2H_{2}O$

Now here, same amount of acid is added to same amount of base.

Now, The reaction equation is equivalent.

The pH of the reaction becomes 7

We know that,

The Universal Indicators absorb Green Colour radiations at pH = 7

Hence, The resultant solution will give the green colour with universal indicator.

(C) is correct option