<u>Answer: </u>
<u>For 1:</u> The volume of HCl required is 6 L.
<u>For 2:</u> The volume of HCl required is 9 L.
<u>For 3:</u> The volume of sulfuric acid required is 4.5 L.
<u>Explanation:</u>
To calculate the volume of acid, we use the equation given by neutralization reaction:
......(1)
where,
are the n-factor, molarity and volume of acid
are the n-factor, molarity and volume of base
We are given:

Putting values in equation 1, we get:

Hence, the volume of HCl required is 6 L.
We are given:

Putting values in equation 1, we get:

Hence, the volume of HCl required is 9 L.
To calculate the volume of acid, we use the equation:

where,
are the normality and volume of acid
are the normality and volume of base
We are given:

Putting values in above equation, we get:

Hence, the volume of sulfuric acid required is 4.5 L.