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 641 of 686
- A. Surface tension is greater than the atmospheric pressure
- B. Viscosity is less than the atmospheric pressure
- C. Vapor pressure equals the atmospheric pressure
- D. Viscosity equals the atmospheric pressure
Explanation: The temperature at which vapor pressure becomes equal to atmospheric pressure is called the boiling point.
Correct answer: Vapor pressure equals the atmospheric pressure- A. 2 H2 (g) + O2 (g) -> 2H2O (l)
- B. C(s) + O2 (g) -> CO2(g)
- C. N2(g) + O2 (g) -> N2O2 (g)
- D. None of these
Explanation: Because heat is absorbed in this reaction. All the other reactions are exothermic as the heat is released during the process.
Correct answer: N2(g) + O2 (g) -> N2O2 (g)- A. H+(aq) + OH−(aq) -> H2O(l)
- B. 1/2 H2(g) -> H(g)
- C. Na(g) -> Na+(g) + 1e−
- D. 1/2 Cl2(g) -> Cl(g)
Explanation: Explanation:Neutralization is always an exothermic reaction. Hence, the correct answer is A.
Correct answer: H+(aq) + OH−(aq) -> H2O(l)- A. C(g) + O2(g) → CO2(g)
- B. N2(g) + 3H2(g) → 2NH3(g)
- C. 2H2O(l) → 2H2(g) + O2(g)
- D. None of the above
Explanation: Explanation:This reaction is endothermic reaction: 2H2O (l) → 2H2 + O2 This reaction is Exothermic reaction, not endothermic.
Correct answer: 2H2O(l) → 2H2(g) + O2(g)- A. Radial.
- B. Angular.
- C. Insoluble.
- D. Soluble
Explanation: The insoluble solid particles can be separated from the liquid by filtration.
Correct answer: Insoluble.- A. KOH
- B. Gypsum
- C. CaCl2
- D. Silica sand
Explanation: The anhydrous calcium chloride will absorb any water (including condensation, vapour etc) in its environment.
Correct answer: CaCl2- A. Cl-
- B. Cl+
- C. Cl2
- D. Cl0
Explanation: A free radical is an atom, molecule or ion that has an unpaired electron.
Correct answer: Cl0- A. Cu2Cl2 and NH4Cl
- B. Al2O3 and NH4Cl
- C. Cu2Cl2 and NH4OH
- D. Cu2Cl2 and Al2O3
Explanation: A is correct since Cu2Cl2 and NH4Cl is used as catalyst for preparation of acrylonitrileB is incorrect because Al2O3 and NH4Cl is not act…
Correct answer: Cu2Cl2 and NH4Cl- A. Nucleophile
- B. Electrophile
- C. Protophile
- D. None of the given options
Explanation: Nucleophiles contain an unshared pair of electrons, and they look for a positive 'centre' to bond with.
Correct answer: Nucleophile- A. Cyano compounds
- B. Nitro compounds
- C. Carbon nitrogen compounds
- D. Nitriles
Explanation: In organic chemistry compounds which contain CN are called nitriles such as CH3CH2CN is called ethanenitrile.
Correct answer: Nitriles- A. 2-aminopropanoic acid
- B. 2-aminoethanoice acid
- C. 2-aminobutane-1,4-dioic acid
- D. 2-aminobutanoic acid
Explanation: The IUPAC name of Alanine is 2-aminopropanoic acid since the amino group is bonded to carbon number 2 and the longest chain is of 5 carbons.
Correct answer: 2-aminopropanoic acid- A. Secondary alcohol, nitrile, and phenol ring
- B. Secondary alcohol, amine, and benzene ring
- C. Secondary alcohol, nitrile, and aryl ring
- D. Primary alcohol, nitrile, and benzene ring
Explanation: The functional groups are: secondary alcohol, nitrile, and benzene/aryl ring.Option A incorrectly mentions phenol as there is no hydroxyl…
Correct answer: Secondary alcohol, nitrile, and aryl ring- A. Sodium hydroxide
- B. Per oxides
- C. Super oxides
- D. Normal oxides
Explanation: A is incorrect as sodium hydroxide is not used for whitening of newspapers.B is correct as per oxides are used to whiten old…
Correct answer: Per oxides- A. Iron
- B. Carbon
- C. Copper
- D. Silver
Explanation: An iron catalyst is used in the Haber process because iron is durable, cheap, and effective at catalysis.
Correct answer: Iron12815. Which one of the following is the correct chemical reaction for Ammonia formationby Haber process?
- A. N2(g) + H2(g) ⇌ 2NH(g)
- B. 2N(g) + 3H2(g) ⇌ NH3(g)
- C. 2N(g) + 3H2(g) ⇌ 2NH3(g)
- D. N2(g) + 3H2(g) ⇌ 2NH3(g)
Explanation: Below is the true reaction of haber's process:N2(g) + 3H2(g) = 2NH3(g)It is a fact and should be memorized.
Correct answer: N2(g) + 3H2(g) ⇌ 2NH3(g)- A. Standard
- B. Normal
- C. Cool
- D. Harsh
Explanation: Nitrogen gas is a molecule with a triple bond between the atoms, which makes Nitrogen unreactive under normal conditions as it takes a lot…
Correct answer: Harsh- A. 46%
- B. 82%
- C. 14%
- D. 17%
Explanation: The Mr of Ammonia (NH3) is 14+3=17It contains ammonia in the percentage of :14/17 x 100 = 82%
Correct answer: 82%- A. 3N2 (g) + 3H2 (g) <=====> 2NH3 (g)
- B. N2 (g) + H2 (g) <=====> NH3 (g)
- C. 3N2 (g) + H2 (g) <=====> 2NH3 (g)
- D. N2 (g) + 3H2 (g) <=====> 2NH3 (g)
Explanation: Ammonia is synthesized in a process called Haber Process by Nitrogen (N2) and Hydrogen (H2) First of all, write the chemical equation for…
Correct answer: N2 (g) + 3H2 (g) <=====> 2NH3 (g)- A. sp3
- B. sp2
- C. sp
- D. All of these
Explanation: In hybridization, carbon's 2s and three 2p orbitals combine into four identical orbitals, now called sp3 hybrids.
Correct answer: sp3- A. sp2
- B. sp3
- C. dsp2
- D. sp
Explanation: Explanation:The linear shape is associated with a set of hybrid orbitals that are sp-hybridized. This option is not correct.
Correct answer: sp