Some Basic Concepts of Chemistry

Some CO2 gas was kept in a sealed container at a pressure of 1 atm and at 273 K. This entire amount of CO2 gas was later passed through an aqueous solution of Ca(OH)2. The excess unreacted Ca(OH)2 was later neutralized with 0.1 M of 40 mL HCl. If the volume of the sealed container of CO2 was x, then x is cm3 (nearest integer). [Given : The entire amount of CO2(g) reacted with exactly half the initial amount of Ca(OH)2 present in the aqueous solution.]

Answer

45

Solution

nHCl = 0.1 0.040 = 4 10-3 mol excess Ca(OH)2 = 2 10-3 mol

CO2 reacted with the other half, equal to this: nCO2 = 2 10-3 mol (1 : 1)

x = 2 10-3 22400 = 44.8 45 cm3

Answer: 45