HNO3 used as a reagent has specific gravity of 1.42g/ml and contains 70% by strength HNO3. Calculate

You have introduced a new term into Chemistry: percent by strength. What in the world is that? Normally, it would be w/w or w/v

Without knowing what you mean, it is not possible to answer the questions.

I too wonder what it means

a)54.6

To calculate the normality of the acid, the volume of acid required to contain a certain amount of pure acid, and the volume of water required to make a specific normality solution, we'll need to use the following formulas:

a) Normality (N) = (Percentage Strength / Equivalent Weight)
Note: The equivalent weight of HNO3 is equal to its molecular weight.

b) Volume of Acid = (Weight of Pure Acid / Specific Gravity)

c) Volume of Water = [(Volume of Conc. Acid x Percentage Strength) / (Desired Normality - Percentage Strength)]

Let's calculate the values step by step:

a) To calculate the normality of the acid:
- The specific gravity of the acid is given as 1.42 g/ml.
- The acid contains 70% strength of HNO3.

Normality = (70 / Molecular Weight of HNO3)

b) To calculate the volume of acid that contains 63g of pure acid:
- The weight of pure acid is given as 63g.
- The specific gravity of the acid is given as 1.42 g/ml.

Volume of Acid = (63 / Specific Gravity of Acid)

c) To calculate the volume of water required to make a 1N solution from 2ml of concentrated HNO3:
- The volume of concentrated HNO3 is given as 2ml.
- The desired normality of the solution is given as 1N.
- The percentage strength of the concentrated acid is already known as 70%.

Volume of Water = [(Volume of Conc. Acid x Percentage Strength) / (Desired Normality - Percentage Strength)]

Now, you can substitute the given values into the respective formulas to find the answers.