PYQSidePowered by
ExamsMy practice
The molarity of 1 L orthophosphoric acid (H3PO4) having 70% purity by weight (specific gravity 1.54 g cm-3) is M. (Molar mass of H3PO4 = 98 g mol-1)
11
Mass of 1 L solution = 1000 mL × 1.54 g mL-1 = 1540 g
Mass of H3PO4 = 70% of 1540 = 1078 g
Moles = 107898 = 11 mol
∴ Molarity = 11 mol1 L = 11 M
Answer: 11
The mass of sodium acetate (CH3COONa) required to prepare 250 mL of 0.35 M aqueous solution is g. (Molar mass of CH3COONa is 82.02 g mol-1)
0.05 cm thick coating of silver is deposited on a plate of 0.05 m2 area. The number of silver atoms deposited on plate are 1023. (At mass Ag = 108, d = 7.9 g cm-3)
A solution of H2SO4 is 31.4% H2SO4 by mass and has a density of 1.25 g/mL. The molarity of the H2SO4 solution is M (nearest integer) [Given molar mass of H2SO4 = 98 g mol-1]
If 50 mL of 0.5 M oxalic acid is required to neutralise 25 mL of NaOH solution, the amount of NaOH in 50 mL of given NaOH solution is g.
Mass of methane required to produce 22 g of CO2 after complete combustion is g. (Given Molar mass in g mol-1 C = 12.0, H = 1.0, O = 16.0)
Volume of 3M NaOH (formula weight 40 g mol-1) which can be prepared from 84 g of NaOH is 10-1dm3.