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11 grade chemistry others

What volume of water should be added to 50ml of HNO3 having density d = 1.5 and 63%
by weight to have 1M solution.
A.750 ml
B.700ml
C.800 ml
D.1400 ml

Profile image of Aniket Singh
1 Year agoGrade
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1 Answer

Profile image of Askiitians Tutor Team
1 Year ago

To solve this problem, we need to determine the concentration of the given nitric acid solution and then calculate how much water should be added to make it a 1M solution.

First, let's find the molarity of the given HNO3 solution:

Calculate the mass of HNO3 in the solution:
Mass of HNO3 = Volume × Density × % by weight of HNO3
= 50 ml × 1.5 g/ml × 0.63
≈ 47.25 grams

Convert the mass of HNO3 to moles using its molar mass:
Molar mass of HNO3 = 1(1) + 14 + 3(16) = 63 g/mol
Moles of HNO3 = Mass of HNO3 / Molar mass of HNO3
= 47.25 g / 63 g/mol
≈ 0.75 moles

Calculate the molarity (M) of the solution:
Molarity (M) = Moles of solute / Volume of solution (in liters)
= 0.75 moles / (50 ml / 1000)
= 15 M

Now, we want to dilute this solution to make it 1M. Let's denote:
V1 = Volume of the initial solution (50 ml)
C1 = Concentration of the initial solution (15 M)
C2 = Concentration of the final solution (1 M)
V2 = Volume of water to be added (unknown)

We'll use the dilution formula:
C1V1 = C2V2

Substituting the values:
15 M × 50 ml = 1 M × (50 ml + V2)
750 ml = 50 ml + V2
V2 = 750 ml - 50 ml
V2 = 700 ml

So, the correct answer is option B. 700 ml of water should be added to 50 ml of the given HNO3 solution to make it a 1M solution.