Question

25.3g of sodium carbonate, Na,C0, is dissolved in enough
water to make 250 mL of solution. If sodium carbonate
dissociates completely, molar concentration of sodium
ion, Na' and carbonate ions, což are respectively (Molar
mass of Na.CO; = 106 g mol!)
(a) 0.955 M and 1.910M (b) 1.910 M and 0.955 M
C) 1.90 M and 1.910M (d) 0.477 M and 0.477 M
(2010)​

Answer 1

Answer:

Number of moles of Na 2CO3= 106/25.3 =0.239 moles

Molarity of solution=

0.25/0.239 =0.956mol/litre

Na2 CO3 ⟶2Na+CO2/3-

∴ Concentration of CO 2−/3 =0.956M

Concentration of Na =2×0.956=1.912M