Question

How much volume of 20 M H2SO4 should be diluted with water to prepare 6 L of 5 MH2S04.
(1)
6.5 L
(2)
15 L
(3)
18.5 L
(4)
3L​

Answer 1

Answer:

if you add V ml of 0.1 M H  

2

​  

SO  

4

​  

 then you are adding 0.01 moles of H  

2

​  

SO  

4

​  

.

in 50mL of 0.1 M NaOH, there are 0.005 moles of NaOH.

The chemical equation for that is :

2NaOH+H  

2

​  

SO  

4

​  

→Na  

2

​  

SO  

4

​  

+2H  

2

​  

O.

0.0025 moles of H  

2

​  

SO  

4

​  

 will neutralize 0.005 moles of NaOH.

So from 0.01V moles of H  

2

​  

SO  

4

added in VmL there will be

0.01V- 0.0025 moles of H  

2  

SO  

4 ​  

left  unused in the total volume of V + 50mL of solutions.

The conc. here will be  

V+50

0.01V−0.0025

×1000=0.05M.

V+50

100v−2.5

=0.05

On solving for V, we get the value :

V = 0.05002 L

V = 50.02 mL

Hence, the correct option is B

Explanation:

Answer 2

Explanation:

Law of Dilution = M1 V1 = M2 V2

• M1= 20 M
• V1 = ?
• M2 = 5 M
• V2 = 6 L
• 20 × V1 = 5 × 6
• 20 × V1 = 30
• V1 = 30 /20
• V1 = 1.5 Litres