The Total solution for NCERT class 6-12
Calculate the molarity of each ofthe following solutions: (a) 30g of Co(NO3)2. 6H2O in 4.3 L of solution (b) 30 mL of 0.5 M H2SO4 diluted to 500 mL.
Molarity is given by:
a) Molar mass of Co (NO3)2.6H2O = 59 + 2 (14 + 3 × 16) + 6 × 18
= 291 g mol−1
∴Molesof Co (NO3)2.6H2O
= 0.103 mol
Therefore, molarity
= 0.023 M
(b) Number of moles present in 1000 mL of 0.5 M H2SO4 = 0.5 mol
∴Numberof moles present in 30 mL of 0.5 M H2SO4
= 0.015 mol
= 0.03 M