250 ml of a sodium carbonate solution contains 2.65 grams of `Na_(2)CO_(3)`. If 10 ml of this solution is diluted to one litre, what is the concentration of the resultant solution (mol. Wt. of Na_(a)`CO_(3)=106`)

Options

A. 0.1M
B. 0.001 M
C. 0.01 M
D. `10^(-4)M`

Answer

B

Explanation

Molarity `= (W(g) xx 1000)/("molecular wt." xx V(mL))`
` = (2.65 xx 1000)/(106 xx 250) = 0.1M`
10mL of this solution is diluted to
`1000 mL M_(1)V_(1) = M_(2)V_(2)`
`10 xx 0.1 = 1000 xx x`
`10 xx 0.1 = 1000 xx x `
`x = (0.1 xx 10)/(1000) = 0.001 M`