Question

147. Volume of water to be added to 150 mL 0.2 M Na2CO3 to make it 0.05 M is
(a) 150 mL (b) 300 mL (c) 450 mL. (d) 600 mL​

Answer 1

Answer:

450mL

Explanation:

M1V1=M2V2

0.05×V1=0.2×150

V1=0.2×150÷0.05

V1=600mL

600mL is the total volume of M2

We have to Subtract 150 from 600 to get the vol of water which need to be added to it to get 0.05M

ie, 600-150= 450mL

Answer 2

Option(c) is correct.

Concept:

Molar concentration, also known as molarity, is defined as the number of moles of solute present in a given number of litres of solution, or moles per litre.

Find:

The volume of water needs to be added to the solution.

Solution:

$M_1V_1=M_2V_2\\0.2*150=0.05*V_2\\V_2=600ml$

Total volume should be $600ml$.

The total amount of water that must be added is

$=600-150\\=450ml$

Hence, the total amount of water that must be added is $450ml$. Option(c) is correct.

Hence, the total amount of water that must be added is $450ml$. Option(a) is incorrect.

Hence, the total amount of water that must be added is $450ml$. Option(b) is incorrect.

Hence, the total amount of water that must be added is $450ml$. Option(d) is incorrect.