All Free Chemistry MCQs with Answers

• A. Spherical
• B. Dumbbell
• C. Complicated
• D. All of these

Explanation: When the angular quantum number is equal to 2, the shape of the orbital gets cloverleaf or we can say it gets complicated in shape.

• A. It forms after a sigma bond
• B. It is formed by parallel overlapping of orbitals
• C. P orbital may form a pi bond
• D. Hybrid orbital forms a pi bond

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

• A. CH4
• B. C2H2
• C. C2H4
• D. All of the above

Explanation: All of the above possess a single covalent bond between carbon and hydrogen. Hence, option D is right option

• A. Pi bond between hybridized orbitals
• B. Sigma bond between hybridized orbitals
• C. Pi bond between unhybridized orbitals
• D. Sigma bond between unhybridized orbitals

Explanation: Option A: Pi bond between hybridized orbitals: In molecular orbital theory, hybridized orbitals can overlap to form sigma bonds.

• A. One sigma and one pi bond
• B. 2 sigma bonds
• C. 2 pi bonds
• D. Half pi and half sigma bond

Explanation: OPTION A: A double bond consists of one sigma bond and one pi bond. A sigma bond is a strong covalent bond formed by the overlap of two…

• A. 3
• B. 2
• C. 1
• D. 0

Explanation: One C=C will have "one" pi bond in it as a double covalent bond consisting of one pi bond and one sigma bond.

• A. 35.5
• B. 37
• C. 4.3
• D. 78

Explanation: c) 4.3:The m/e value of 4.3 is an unusual and specific value. It is not commonly associated with any ions or fragments that would be…

• A. Propane
• B. Butane
• C. 2-methylpropane
• D. 2,2 - dimethylpropane

Explanation: b) Butane:Butane is a four-carbon alkane with the molecular formula C4H10.

• A. C2H4
• B. C5H11N
• C. C7H13O
• D. C2H5F

Explanation: b) C5H11N:The molecular ion occurs at m/e 86. The empirical formula C5H11N corresponds to the compound pentylamine, which has a molecular…

• A. CuCl2
• B. ZnCl2
• C. HgCl2
• D. C4H9NH4+Cl-

Explanation: d) C4H9NH4+Cl- (Tetra-n-butylammonium chloride):Tetra-n-butylammonium chloride is a quaternary ammonium salt and does not contain a metal…

• A. Texture of surface
• B. Hardness
• C. Passing X-rays
• D. Placing in magnetic field

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

• A. Size
• B. Position
• C. Shape
• D. Structure

Explanation: The breakdown or fragmentation of molecular ions from natural products, typically obtained by techniques such as mass spectrometry, can…

• A. Lyman
• B. Paschen
• C. Brackett
• D. Pfund
• E. Balmer

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

• A. Shells
• B. Energy levels
• C. Sub shells
• D. All of these options are correct

Explanation: A. Shells (Incorrect): Fine lines in a line spectrum are indicative of transitions between energy levels within an atom, not the presence…

• A. 10-8 m
• B. 10-1 m
• C. 10-11 m
• D. 10-13 m

Explanation: The radius of an electron orbit in a hydrogen atom, as estimated by the Bohr model, is approximately 0.529 angstroms.

• A. Shells
• B. Energy Levels
• C. Subshells
• D. All of these

Explanation: Option A is incorrect because electrons can't jump between "shells". Option B is incorrect because the line spectrum is caused by the…

• A. Balmer
• B. Pfund
• C. Paschen
• D. none of these

Explanation: When the electron series terminates at 4th orbit, the 'Bracket series' is obtained.

• A. Balmer
• B. Pfund
• C. Paschen
• D. None of these options are correct

Explanation: None of these options are correct. When an electron series terminates on the 4th orbit, it corresponds to the Lyman series.

• A. Shells
• B. Energy levels
• C. Sub shells
• D. All of these

Explanation: Presence of subshells is shown by several fine lines on the line spectrum.

• A. 10
• B. +1
• C. -1
• D. Zero

Explanation: The potential of the standard hydrogen electrode (SHE) is defined as 0 V under standard conditions.