All Free Chemistry MCQs with Answers
Every Chemistry question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,720 questions · page 611 of 686
- A. 3
- B. 4
- C. 6
- D. 1
Explanation: Option B "4"It is the total number of electron pair donated by ligands to the central metal atom or ion .
Correct answer: 4- A. Coinage metals
- B. Nobel metals
- C. Transition metals
- D. Alkali metals
Explanation: D-block elements are call transition metals while f block are called inner transition elements.
Correct answer: Transition metals- A. Sc
- B. Y
- C. Cd
- D. Co
Explanation: Option D is correct since only Co is a typical transition element.Group 2B (Zn, Cd, and Hg) and group 3B(Sc, Y, and La) are nontypical…
Correct answer: Co- A. Orbitals of f-subshell
- B. Orbital's of d-sub shell
- C. Orbitals of p-subshell
- D. Both A and B
Explanation: This option is correct because it covers both option A and option B which are true.
Correct answer: Both A and B- A. Ionization state
- B. Oxidation state
- C. Electronic configuration
- D. Formation of complexes
Explanation: Lanthanides and actinides are both transition elements and form complexes.
Correct answer: Formation of complexes- A. Na
- B. Co
- C. Ba
- D. Ra
Explanation: "Cobalt" shows variable transition states and has a partially filled d-orbital therefore it is a transition element hence the answer is B.
Correct answer: Co- A. 48
- B. 32
- C. 58
- D. 28
Explanation: There are "38" d-block elements that show variable oxidation states and have partially filled d-orbitals hence the answer is A.
Correct answer: 48- A. Diamagnetic
- B. Paramagnetic
- C. Good conductor
- D. Ferromagnetic
Explanation: Compounds which have one or more unpaired electrons are attracted to poles of magnets and such compounds are called paramagnetic…
Correct answer: Paramagnetic- A. Cr
- B. Mn
- C. Fe
- D. All of these
Explanation: The presence of unpaired electrons causes a molecule to be paramagnetic.
Correct answer: Cr- A. Propene
- B. Propan-1-ol
- C. Propan-2-ol
- D. Potassium Propoxide
Explanation: a) Propene:When 2-bromopropane is heated with concentrated alcoholic potassium hydroxide (KOH), it undergoes an elimination reaction known…
Correct answer: Propene- A. C2H4
- B. C2H5OH
- C. C2H4ClOH
- D. C2H6
Explanation: A is correct option because When ethyl chloride is reacted with alcoholic KOH, ethylene is formed.
Correct answer: C2H4- A. Combustion reaction
- B. Oxidation
- C. Elimination reaction
- D. Addition reaction
Explanation: Tertiary alcohols undergo dehydration/elimination reaction to form alkenes under specific conditions i.e., heat + concentrated sulphuric…
Correct answer: Elimination reaction- A. Substitution reaction
- B. Elimination reaction
- C. Addition reaction
- D. Replacement reaction
Explanation: In elimination reactions, molecules are removed from compounds without the addition of subsequent molecules.
Correct answer: Elimination reaction- A. H+ (aq) + OH-(aq) -> H2O(l)
- B. H2 (g) + ½ O2 (g) -> H2O (l)
- C. H2O(g) + H2O(l)
- D. H2O(s) -> H2O(l)
Explanation: The reaction H₂(g) +1/2 O₂(g) → H₂O(l) shows the standard enthalpy change for the formation of water, where △H is the heat of formation of…
Correct answer: H2 (g) + ½ O2 (g) -> H2O (l)- A. Enthalpy of atomization
- B. Enthalpy of fusion
- C. Enthalpy of vaporization
- D. Enthalpy of formation
Explanation: Option A, enthalpy of atomization, is the energy required to completely separate all the atoms in a chemical substance.
Correct answer: Enthalpy of atomization- A. Heat of fusion
- B. Heat of vapourization
- C. Heat of sublimation
- D. Heat of evaporation
Explanation: The heat of fusion is the enthalpy change required to melt one mole of a solid substance at its melting point The heat of vaporization is…
Correct answer: Heat of sublimation- A. Enthalpy of formation
- B. Enthalpy of combustion
- C. Enthalpy of neutralization
- D. Enthalpy of sublimation
Explanation: The enthalpy of formation is the standard reaction enthalpy for the formation of the compound from its elements (atoms or molecules) in…
Correct answer: Enthalpy of formation- A. Enthalpy of combustion
- B. Enthalpy of solution.
- C. Enthalpy of formation
- D. Enthalpy of atomization
Explanation: Combustion reactions release heat, so the enthalpy change of the system, H, will always be negative.
Correct answer: Enthalpy of combustion- A. ΔG
- B. ΔH
- C. ΔE
- D. ΔH-ΔE
Explanation: Enthalpy change is the heat absorbed by a substance at constant pressure. ΔH= ΔU + PΔV= Q - PΔV + PΔV = Q
Correct answer: ΔH12220. ΔH is the difference in the number of moles of reactants and products in a reaction which is _.
- A. Solid phase
- B. Liquid phase
- C. Gaseous phase
- D. Plasma phase
Explanation: ∆n is equal to the total moles of gas on the products side - total moles of gas on the Reactant side.
Correct answer: Gaseous phase