Question

Calculate which is more concentrated 20G of alkali in 250cm3 of solution or 10G of the same alkali in 50cm3 of solution. SHOW YOUR WORKING

Answer 1

Answer:

Answer : The solution A is more concentrated than the solution B.

Explanation : Given,

Mass of alkali in solution A = 20 g

Mass of alkali in solution B = 10 g

Volume of solution in solution A = 250cm^3=250ml250cm

3

=250ml

Volume of solution in solution B= 500cm^3=500ml500cm

3

=500ml

First we have to calculate the concentration of both the solution A and B.

For solution A :

\text{Concentration}=\frac{\text{Mass of alkali in solution A}\times 1000}{\text{Molar mass of alkali}\times \text{Volume of solution}}Concentration=

Molar mass of alkali×Volume of solution

Mass of alkali in solution A×1000

Let the molar mass of alkali be, 'M'.

\text{Concentration}=\frac{20g\times 1000}{M\times 250ml}=\frac{80}{M}Concentration=

M×250ml

20g×1000

=

M

80

For solution B :

\text{Concentration}=\frac{\text{Mass of alkali in solution B}\times 1000}{\text{Molar mass of alkali}\times \text{Volume of solution}}Concentration=

Molar mass of alkali×Volume of solution

Mass of alkali in solution B×1000

\text{Concentration}=\frac{10g\times 1000}{M\times 500ml}=\frac{20}{M}Concentration=

M×500ml

10g×1000

=

M

20

From the above, we conclude that the value of solution A more than the solution B. So, the solution A more concentrated as compared to the solution B.

Hence, the solution A is more concentrated than the solution B