Free Chemical Process Principles MCQs with Answers

• A. Mass number
• B. Atomic number
• C. Atomic weight
• D. Metallic characteristics

Explanation: The modern periodic table is arranged by increasing atomic number, which is the number of protons in the nucleus.

• A. Mole fraction
• B. Normality
• C. Molarity
• D. Molality

Explanation: Molarity is commonly convenient because it directly relates moles of solute to a measured volume of solution and is widely used in…

• A. Evaporation
• B. Melting
• C. Vaporisation
• D. Sublimation

Explanation: Sublimation is the direct conversion of a solid into vapour without passing through the liquid state.

• A. 22.4 litres
• B. 22400 litres
• C. 22.4 c.c
• D. 359 litres

Explanation: At STP, one gram mole of an ideal gas occupies the molar volume 22.4 L, equivalent to 22,400 cm³.

• A. 1
• B. 0
• C. 16
• D. 44

Explanation: At steady state, the amount of material inside the system does not change with time, so accumulation is zero.

• A. 650
• B. 700
• C. 600
• D. 375

Explanation: Each gas expands from 0.5 L to the final 1 L vessel, so its partial pressure is halved: 350 mm Hg for hydrogen and 300 mm Hg for oxygen.

• A. 0°C
• B. 0°K
• C. -136.5°C
• D. -136.5°K

Explanation: At constant pressure, Charles's law states that volume is proportional to absolute temperature.

• A. 28.6
• B. 30.0
• C. 30.6
• D. 32.6

Explanation: The mixture molecular weight is the mole-fraction-weighted average: 0.15(44) + 0.05(32) + 0.80(28) = 30.6 g/mol.

• A. Hydration
• B. Hydrolysis
• C. Electrolysis
• D. Dialysis

Explanation: Hydrolysis occurs when ions from a salt react with water, producing acidic or alkaline solutions.

• A. 105 BTU
• B. 105 kcal
• C. 109 BTU
• D. 109 kcal

Explanation: A therm is a unit of heat equal to 100,000 BTU, commonly written as 10^5 BTU. It is not 10^5 kcal.

• A. 32 kg
• B. 80 kg
• C. 64 kg
• D. 90 kg

Explanation: Water contains 32 kg of oxygen per 36 kg of H2O by mass, or an oxygen mass fraction of 8/9.

• A. Temperature
• B. Pressure
• C. Solute concentration
• D. Dilution of the solution

Explanation: Normality is based on equivalents per unit volume, so temperature, concentration and dilution can alter it through volume or composition…

• A. Inversely proportional to the mass of solvent
• B. Directly proportional to the mole of solute
• C. Both A. and B.
• D. Neither A. nor B.

Explanation: The freezing-point depression is given by ΔTf = Kf m, where molality is moles of solute per kilogram of solvent.

• A. 35 c.c acid and 15 c.c base
• B. 20 c.c acid and 25 c.c base
• C. 15 c.c acid and 35 c.c base
• D. 30 c.c acid and 30 c.c base

Explanation: For equal-normality acid and base, the heat released is proportional to the smaller reacting volume.

• A. Increases
• B. Decreases
• C. Remains unchanged
• D. Either A. or B.; depends on the type of solution

Explanation: Dissolved solutes commonly have lower specific heat than water, so increasing concentration usually lowers the specific heat of an aqueous…

• A. Mass number
• B. Number of neutrons
• C. None of these
• D. Atomic mass

Explanation: Isotopes are atoms of the same element, so they have the same atomic number but different numbers of neutrons and consequently different…

• A. 0.01
• B. 0.1
• C. 1
• D. 10

Explanation: One degree Brix represents one gram of sucrose per 100 grams of sugar solution, or approximately 1% sugar by mass.

• A. 0
• B. 1
• C. 7
• D. 10

Explanation: One gram of hydrogen ion is approximately one mole, so the concentration is 1 mol/L. Since pH = -log[H+], the pH is -log(1)=0.

• A. 1/9
• B. 8/9
• C. 1/2
• D. 5/9

Explanation: For equal masses, hydrogen gives eight times as many moles as methane because their molar masses are 2 and 16 g/mol.

• A. 44/22400
• B. 22.4/44
• C. 44/22.4
• D. None of these

Explanation: At normal conditions, one kilomole of gas occupies about 22.4 Nm³. Therefore CO2 density is 44/22.4 kg/Nm³, approximately 1.96 kg/Nm³.