Answer: D40% HCL is mixed with 60% HCL in the ratio 4:1 to get 44% hcl.44% and 32% are mixed in the ratio 2:1
Thus the average, we have (x-32)/(44-x) =2/1 => x=40%.
i.e 50 L of water has been added to a certain quantity of 40% hcl to get 20% hcl. The quantity has to be 50 L. Before the 25L was removed the quantity was 75 L. This, we got by mixing 25L of 32% hcl with 50% L of 44% hcl.
The 44% hcl is got by mixing 40% hcl and 60% hcl in the ratio 4:1. i.e 40L of 40% and 10 L of 60% hcl.
The data and calculations are tabulated below:-
Strength (%)
|
40 |
44 |
60 |
Strength (%) |
40 |
44 |
60 |
Ratio of quantities
|
4 |
5 |
1 |
Quantity |
40 |
50 |
10 |
Strength (%) |
32 |
40 |
44 |
Strength (%)
|
32 |
40 |
44 |
Ratio of quantities
|
1 |
3 |
2 |
Quantity |
25 |
75 |
50 |
Strength (%)
|
0 |
20 |
40 |
Strength (%)
|
0 |
20 |
40 |
Ratio of quantities
|
1 |
|
1 |
Quantity |
50 |
|
50 |