Question

2. How many ml of a 50% w/v acetic acid solution are required to prepare 1 L of 5% w/v acetic acid? 3. How many ml of concentrated HNOs are required to prepare 2L of 0.15N HNOs? 4. How many milliliters of a stock solution of 20% w/v NaOH are required to prepare 800 ml of a 2.5% w/v solution? 5. Suppose that you start with a 5X solution A and you want a final volume of 10 microliters of 1X solution A. How much solution A will you need?

Answer 1

2)

Answer

100ml

Explanation

Dilution formula is as follows

C1×V1 = C2 × V2

C1 = Initial solution concentration , 50% w/v

V1 = Initial solution volume , ?

C2 = Final solution concentration, 5%

V2 = Final solution volume , 1L

V1 = C2×V2/C1

= 5% × 1L / 50%

= 0.1L

= 100ml

3)

Answer

18.99ml

Explanation

Normality of concentrated HNO3(C1) = 15.8N

Volume of concentrated HNO3 required(V1) = ?

Normality of final solution required(C2) = 0.15N

Volume of concentrated HNO3 required(V1) = 2L

V1 = C2 × V2/C1

= 0.15N × 2L /15.8N

= 0.01899L

= 18.99ml

4)

Answer

100ml

Explanation

C1 = 20% w/v

V1 = ?

C2 = 2.5 %

V2 = 800ml

V1 = 2.5% w/v × 800ml/20% w/v

= 100ml

5)

Answer

2 $\mu$L

Explanation

C1 = 5X

V1 = ?

C2 = 1X

V2 = 10$\mu$L

V1 = 1X × 10$\mu$L /5X

V1 = 2$\mu$L