25.3 g of sodium carbonate, `Na_(2)CO_(3)` is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissociates completely, molar concentration of sodium ions, `Na^(+)` and carbonate ions, `CO_(3)^(2-)` are respectively (Molar mass of `NaCO_(3)=106g mol^(-1)`)

Options

A. 1.90 M and 1.910 M
B. 0.477 M and 0.0477 M
C. 0.955 M and 1.910 M
D. 1.910 M and 0.955 M

Answer

D

Explanation

Molarity of solution `= (25.3 xx 1000)/(106 xx 250)`
` = 0.955 M`
`Na_(2) CO_(2) to 2N^(+) + CO_(3)^(2-)`
`[Na^(+)] = 2 xx 0.955 M = 1.910 M`
` [CO_(3)^(2-)] = 0.955 M`