All Free Chemistry MCQs with Answers

• A. Graphite
• B. Copper
• C. Iron
• D. Silver

Explanation: The graphite anode has no reaction with chlorine, which is liberated at the anode.

• A. Free charge
• B. Electron
• C. Protons
• D. Zinc ions

Explanation: Option BCu+2 ions from the solution pick up the ELECTRONS at Cu electrode and get reduced to copper atoms ,hence Cu acts as a cathode and…

• A. Graphite
• B. Copper
• C. Iron
• D. Silver

Explanation: In a Down's cell, which is an electrolytic cell used for the production of sodium metal through the electrolysis of molten sodium chloride…

• A. Free electrons
• B. Positive ions
• C. Negative ions
• D. Both Options B and C are correct

Explanation: In electrolysis, current is carried through the electrolytic solution inside the cell by positive and negative ions using…

• A. Electrons
• B. Charges
• C. Energy
• D. Hydrogen ions

Explanation: Redox reactions (oxidation-reduction reactions) are actually the transfer of electrons.

• A. Sodium
• B. Hydrogen
• C. Chlorine
• D. Oxygen

Explanation: Chloride ions (Cl⁻) are attracted to the positive electrode (anode) during the electrolysis of a dilute solution of NaCl.

• A. Copper sulphate
• B. Copper chloride
• C. Zinc Chloride
• D. Zinc Sulphate

Explanation: Zinc, in a voltaic cell, is always dipped in zinc sulfate to get an excess of Zn2+ ions.

• A. (NH4)2Cr2O7
• B. K2Cr2O7
• C. Zn(ClO3)2
• D. KClO3

Explanation: This compound, also known as ammonium dichromate, decomposes upon heating to form chromium (lll) oxide, nitrogen gas, and water vapor.

• A. C(s) + H2O(g) -> CO(g) +2H2(g)
• B. CH3O(l) + CH3CO2H(l) -> CH2CO2CH2(l) + H2O (l)
• C. Cu2+(aq) + 4NH2(aq) -> Cu(NH2)23+ (aq)
• D. N2O4(g) -> 2NO2

Explanation: The units of Kc are dependent upon the number of moles of (only of gases and liquids, not solids like in option A) reactants and products.

• A. Extent of reaction
• B. Direction of reaction
• C. Both A and B
• D. None of the above

Explanation: The explanation for this question will be added soon.

• A. KC
• B. K
• C. Kp
• D. None of these

Explanation: Option C is correct since equilibrium constant Kp represents the extent of the forward reaction in terms of the partial pressures of the…

• A. Stability
• B. Reactivity
• C. Compressibility
• D. Instability

Explanation: The equilibrium constant for the decomposition of ozone to oxygen is 1055 at 25°C.2O3 → 3O2 Kc= 1055 at 25°CIt infers that at room…

• A. High
• B. Low
• C. Negligible
• D. None of these

Explanation: The tendency of an irreversible reaction to go in the reverse direction is negligible.

• A. Maximum
• B. Minimum
• C. Zero
• D. Negligible

Explanation: OPTION A: Maximum is incorrect because, at equilibrium, the rate of the forward and reverse reactions is equal, so there is no net change…

• A. Units
• B. No Units
• C. Both options A and B are correct
• D. A negative value

Explanation: The equilibrium constant formula is kc= concentration of right-hand-side / left-hand-side.

• A. Negative value
• B. Large value
• C. No units
• D. Units

Explanation: OPTION A: A small (negative) Kc value (less than 1) indicates that there are more reactants than products at equilibrium.

• A. Kc
• B. K
• C. Kp
• D. None of these

Explanation: Option A is wrong because Kc is not the equilibrium constant for ideal gases in terms of partial pressure.

• A. Reactants over products
• B. Products over reactants
• C. Product times Reactants
• D. None of these

Explanation: At 'equilibrium', the rate of the forward and reverse reactions are equal.

• A. No Reaction
• B. Backward Reaction
• C. Little Forward Reaction
• D. Complete Reaction

Explanation: A very small value of the equilibrium constant, Kc, indicates that the forward reaction (formation of products) is **very weak** compared…

• A. Irreversible
• B. Unidirectional
• C. Multidirectional
• D. Reversible

Explanation: A reversible reaction is one in which the conversion of reactants to products and the conversion of products to reactants occur…