All Free Chemistry MCQs with Answers

• A. P.E +K.E
• B. P.E+heat enrgy
• C. K.E+heat energy
• D. P.E+mechanical

Explanation: Explanation: The total energy of a system is the sum of its potential energy (P.E) and kinetic energy (K.E).

• A. delta H=qo
• B. delta E=q+w
• C. Delta E=q *v
• D. all of these

Explanation: Explanation: The first law of thermodynamics states that the change in internal energy (Delta E) of a system equals the heat added to the…

• A. Spontaneous reaction
• B. non spontaneous
• C. Endothermic
• D. exothermic

Explanation: Explanation: This reaction involves the displacement of copper from copper sulfate by zinc, which occurs spontaneously as zinc is more…

• A. -787KJ/mole.
• B. 787J/mole
• C. 780KJ/mole
• D. 790KJ/mole

Explanation: Explanation: The lattice energy of NaCl is typically around -787 kJ/mol, representing the energy released when gaseous ions combine to…

• A. q=m x s x delta T
• B. q=delta T
• C. q=m x v x delta T
• D. q=pv

Explanation: Explanation: This equation represents the heat transferred (q) when a substance's temperature changes (delta T) with specific heat…

• A. combustion
• B. formation of compound
• C. dissolution of ionic compound
• D. dilution of a solution

Explanation: Explanation: Dissolving an ionic compound in water often releases energy, resulting in a negative ΔH.

• A. both a & b
• B. delta H=Delta E
• C. delta H>Delta E
• D. both a and b

Explanation: Explanation: During the interconversion of states (solid to liquid or vice versa), there's usually a transfer of energy as heat (ΔH)…

• A. delta H lattice=delta Hf - delta Hx
• B. delta H lattice=delta Hf +delta Hx
• C. delta H lattice=delta a +delta v
• D. delta H lattice = delta H -delta sol

Explanation: Explanation: The enthalpy change for the formation of an ionic compound (ΔH lattice) equals the enthalpy change of formation of ions (ΔHf)…

• A. delta Hf
• B. Delta H latt
• C. detla H comb
• D. all of these

Explanation: Hess's law involves the principle that the total enthalpy change of a reaction is independent of the pathway taken and depends only on the…

• A. 10%
• B. 16%
• C. 13%
• D. 25%

Explanation: The Haber process is an industrial method for the synthesis of ammonia (NH3) from nitrogen (N2) and hydrogen (H2) gases.

• A. Al2O3
• B. Actinium oxide
• C. Cr2O3
• D. All of these

Explanation: Iron is indeed used as a catalyst in the synthesis of ammonia by the Haber process.

• A. Unidirectional
• B. Reversible process
• C. Non-real process
• D. All of these

Explanation: Spontaneous reactions proceed in one direction only, from reactants to products, without the need for external intervention once…

• A. H2 > H1
• B. H1 > H2
• C. H1 = H2
• D. No relationship

Explanation: he information provided reveals two crucial aspects:The reaction is exothermic: The enthalpy change (ΔHc) is negative (-1368 kJ/mol).

• A. KOH and NaOH
• B. HCl and Ba(OH)2
• C. Ca(OH)2 and CH3COOH
• D. H2SO4 and KOH

Explanation: The enthalpy of neutralization is the heat evolved when an acid and a base react to form one mole of water under standard conditions…

• A. C
• B. Fe
• C. Pt
• D. Cu

Explanation: In a bomb calorimeter, the ignition coil is typically made of platinum (Pt).

• A. ΔH = ΔE + PΔV
• B. q + w = ΔH
• C. ΔE = q - w
• D. ΔН +ΔЕ = w

Explanation: The first law of thermodynamics states that the total energy of a closed system remains constant.

• A. Unit
• B. Zero
• C. < zero
• D. Between Zero and one

Explanation: The enthalpies of free elements in their standard states are defined as zero.

• A. Spontaneous and endothermic
• B. Spontaneous and exothermic
• C. Non-spontaneous and endothermic
• D. Non-spontaneous and exothermic

Explanation: The enthalpy of combustion of a substance refers to the heat released or absorbed when one mole of the substance undergoes complete…

• A. -130.10 kJ
• B. -48.06 kJ
• C. +48.06 kJ
• D. +130.10 kJ

Explanation: We can use Hess's law to manipulate the given reactions and their enthalpy changes to arrive at the enthalpy change of formation of…

• A. Thermal energy is converted into kinetic energy of water molecules
• B. Pressure of water molecules increases
• C. The piston is pushed up
• D. All of the above

Explanation: This is the correct answer. Let's break down why each individual option is true:Thermal energy is converted into kinetic energy of water…