Stoichiometry Objective Questions and Answers

162. The vapor pressure of the solvent decreased by 10 mm Hg, when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. What should be the mole fraction of the solvent, if the decrease in vapor pressure of the solvent is required to be 20 mm Hg.?

163. Specific gravity on API scale is given by the relation(where, G = specific gravity at 15.5°C).

A. °API = 200(G - 1)

B. °API = (141.5/G) - 131.5

C. °API = (140/G) - 130

D. °API = 145 - (145/G)

Discussion

164. 1 kg/m² is equal to __________ mm water column.

165. The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. The temperature at which the above mixture will exert a pressure of one standard atm. is

A. Less than 100°C

B. 100°C

C. Between 100 and 110°C

D. 110.6°C

Discussion

166. Solutions having the same osmotic pressure are called __________ solutions.

167. Pick out the wrong unit conversion.

A. 1 atm = 760 mm Hg = 29.92 inch Hg = 14.7 psi = 1.013 bar = 1.013 kgf/cm²

B. 1 kPa = 100 bar

C. 1 mm Hg = 1 torr = 133.3 Pa

D. None of the above

Discussion

168. A sample of well water contains 140 gm/m³ Ca²⁺ ions and 345 gm/m³ Na⁺ ions. The hardness of the sample of water, expressed in terms of equivalent CaCO₃ in gm/m³ is (assuming atomic masses of Ca : 40, Na : 23, C : 12, O : 16)

Chemical Engineering Objective Questions { Stoichiometry }