Physical chemistry

Q#1: Which branch of chemistry deals with the study of energy changes?
(A) Organic chemistry
(B) Inorganic chemistry
(C) Physical chemistry
(D) Analytical chemistry
Answer: (C) Physical chemistry

Q#2: Which law states that energy can neither be created nor destroyed?
(A) First law of thermodynamics
(B) Second law of thermodynamics
(C) Third law of thermodynamics
(D) Zeroth law of thermodynamics
Answer: (A) First law of thermodynamics

Q#3: The unit of entropy is:
(A) Joule
(B) Joule per kelvin
(C) Kelvin
(D) Calorie
Answer: (B) Joule per kelvin

Q#4: Which quantity measures the disorder of a system?
(A) Enthalpy
(B) Free energy
(C) Entropy
(D) Internal energy
Answer: (C) Entropy

Q#5: Which process occurs at constant pressure?
(A) Isochoric
(B) Isothermal
(C) Adiabatic
(D) Isobaric
Answer: (D) Isobaric

Q#6: The SI unit of pressure is:
(A) Bar
(B) Atmosphere
(C) Pascal
(D) Torr
Answer: (C) Pascal

Q#7: Which gas law relates pressure and volume?
(A) Charles’s law
(B) Boyle’s law
(C) Avogadro’s law
(D) Graham’s law
Answer: (B) Boyle’s law

Q#8: The value of absolute zero is:
(A) 0°C
(B) –100°C
(C) –273°C
(D) –273 K
Answer: (C) –273°C

Q#9: Which law relates volume and temperature at constant pressure?
(A) Boyle’s law
(B) Avogadro’s law
(C) Gay-Lussac’s law
(D) Charles’s law
Answer: (D) Charles’s law

Q#10: The number of molecules in one mole is called:
(A) Faraday constant
(B) Avogadro number
(C) Gas constant
(D) Boltzmann constant
Answer: (B) Avogadro number

Q#11: Which equation represents the ideal gas law?
(A) PV = nRT
(B) P₁V₁ = P₂V₂
(C) V/T = constant
(D) P/T = constant
Answer: (A) PV = nRT

Q#12: The SI unit of energy is:
(A) Calorie
(B) Erg
(C) Joule
(D) Watt
Answer: (C) Joule

Q#13: Which process has no heat exchange with surroundings?
(A) Isothermal
(B) Isobaric
(C) Isochoric
(D) Adiabatic
Answer: (D) Adiabatic

Q#14: The tendency of a reaction to occur spontaneously is measured by:
(A) Enthalpy
(B) Entropy
(C) Gibbs free energy
(D) Internal energy
Answer: (C) Gibbs free energy

Q#15: Which symbol represents enthalpy?
(A) U
(B) G
(C) S
(D) H
Answer: (D) H

Q#16: Which unit is used for rate of reaction?
(A) mol L⁻¹
(B) mol L⁻¹ s⁻¹
(C) s⁻¹
(D) L mol⁻¹ s⁻¹
Answer: (B) mol L⁻¹ s⁻¹

Q#17: Which factor does NOT affect the rate of reaction?
(A) Temperature
(B) Concentration
(C) Catalyst
(D) Colour of reactants
Answer: (D) Colour of reactants

Q#18: The time taken for half of the reactant to react is called:
(A) Reaction time
(B) Rate constant
(C) Half-life
(D) Activation time
Answer: (C) Half-life

Q#19: Which order reaction has constant half-life?
(A) Zero order
(B) First order
(C) Second order
(D) Third order
Answer: (B) First order

Q#20: The Arrhenius equation relates rate constant with:
(A) Pressure
(B) Concentration
(C) Temperature
(D) Volume
Answer: (C) Temperature

Q#21: Which term represents minimum energy required for reaction?
(A) Free energy
(B) Enthalpy
(C) Activation energy
(D) Internal energy
Answer: (C) Activation energy

Q#22: Which type of catalyst lowers activation energy?
(A) Positive catalyst
(B) Negative catalyst
(C) Homogeneous catalyst
(D) Enzyme
Answer: (A) Positive catalyst

Q#23: Which unit is used for equilibrium constant?
(A) Always unitless
(B) Joule
(C) Pascal
(D) Kelvin
Answer: (A) Always unitless

Q#24: Which principle explains effect of concentration on equilibrium?
(A) Raoult’s law
(B) Henry’s law
(C) Le Chatelier’s principle
(D) Hess’s law
Answer: (C) Le Chatelier’s principle

Q#25: The pH of a neutral solution at 25°C is:
(A) 5
(B) 6
(C) 7
(D) 8
Answer: (C) 7

Q#26: Which solution has pH less than 7?
(A) Neutral
(B) Basic
(C) Acidic
(D) Buffer
Answer: (C) Acidic

Q#27: The logarithmic measure of hydrogen ion concentration is:
(A) pKa
(B) pKb
(C) pOH
(D) pH
Answer: (D) pH

Q#28: Which law relates vapor pressure and mole fraction?
(A) Henry’s law
(B) Raoult’s law
(C) Dalton’s law
(D) Graham’s law
Answer: (B) Raoult’s law

Q#29: Which colligative property depends on number of particles?
(A) Viscosity
(B) Surface tension
(C) Boiling point elevation
(D) Density
Answer: (C) Boiling point elevation

Q#30: The depression in freezing point is directly proportional to:
(A) Nature of solvent
(B) Nature of solute
(C) Number of solute particles
(D) Volume of solution
Answer: (C) Number of solute particles

Q#31: Which property is used to determine molar mass?
(A) Conductivity
(B) Osmotic pressure
(C) Surface tension
(D) Viscosity
Answer: (B) Osmotic pressure

Q#32: The SI unit of rate constant for first-order reaction is:
(A) mol L⁻¹ s⁻¹
(B) L mol⁻¹ s⁻¹
(C) s⁻¹
(D) mol L⁻¹
Answer: (C) s⁻¹

Q#33: Which electrode is used in pH measurement?
(A) Calomel electrode
(B) Glass electrode
(C) Hydrogen electrode
(D) Silver electrode
Answer: (B) Glass electrode

Q#34: Which type of solution obeys Raoult’s law?
(A) Ideal solution
(B) Non-ideal solution
(C) Colloidal solution
(D) Saturated solution
Answer: (A) Ideal solution

Q#35: Which type of electrolyte conducts electricity strongly?
(A) Weak electrolyte
(B) Non-electrolyte
(C) Strong electrolyte
(D) Solid electrolyte
Answer: (C) Strong electrolyte

Q#36: The unit of conductance is:
(A) Ohm
(B) Siemens
(C) Volt
(D) Ampere
Answer: (B) Siemens

Q#37: Which law relates conductivity with concentration?
(A) Kohlrausch’s law
(B) Henry’s law
(C) Faraday’s law
(D) Hess’s law
Answer: (A) Kohlrausch’s law

Q#38: Which cell converts chemical energy into electrical energy?
(A) Electrolytic cell
(B) Fuel cell
(C) Galvanic cell
(D) Photovoltaic cell
Answer: (C) Galvanic cell

Q#39: Which electrode is anode in a galvanic cell?
(A) Positive electrode
(B) Negative electrode
(C) Neutral electrode
(D) Reference electrode
Answer: (B) Negative electrode

Q#40: Which process occurs at cathode?
(A) Oxidation
(B) Reduction
(C) Neutralization
(D) Hydrolysis
Answer: (B) Reduction

Q#41: Which law gives the amount of substance deposited during electrolysis?
(A) Boyle’s law
(B) Ohm’s law
(C) Faraday’s first law
(D) Hess’s law
Answer: (C) Faraday’s first law

Q#42: The unit of electromotive force (EMF) is:
(A) Ampere
(B) Ohm
(C) Volt
(D) Coulomb
Answer: (C) Volt

Q#43: Which phenomenon explains adsorption of gases on solids?
(A) Absorption
(B) Adsorption
(C) Diffusion
(D) Osmosis
Answer: (B) Adsorption

Q#44: Which type of adsorption involves weak forces?
(A) Chemisorption
(B) Physisorption
(C) Absorption
(D) Ion adsorption
Answer: (B) Physisorption

Q#45: Which theory explains adsorption on solid surfaces?
(A) Arrhenius theory
(B) Langmuir adsorption theory
(C) Collision theory
(D) Valence bond theory
Answer: (B) Langmuir adsorption theory

Q#46: The SI unit of surface tension is:
(A) N/m
(B) J/m²
(C) Pa
(D) kg/m
Answer: (A) N/m

Q#47: Which factor increases rate of adsorption?
(A) Decrease in pressure
(B) Increase in temperature
(C) Increase in surface area
(D) Decrease in surface area
Answer: (C) Increase in surface area

Q#48: Which law states total pressure is sum of partial pressures?
(A) Boyle’s law
(B) Henry’s law
(C) Graham’s law
(D) Dalton’s law
Answer: (D) Dalton’s law

Q#49: Which phenomenon occurs in colloids?
(A) Osmosis
(B) Diffusion
(C) Tyndall effect
(D) Crystallization
Answer: (C) Tyndall effect

Q#50: Which unit is used for viscosity?
(A) Poise
(B) Newton
(C) Joule
(D) Pascal
Answer: (A) Poise