Chemistry (General Concepts) MCQs with Answers

Select the spontaneous reaction among the following:

• A.Emission of α-particles from polonium
• B.Electrolysis of water
• C.Photosynthesis in plants
• D.Rusting of iron in the presence of moisture

Half-life of a radioactive substance depends upon?

• A.Temperature
• B.Pressure
• C.Nature of substance
• D.Amount of substance

Repeated extraction using a portion of solvent is more?

• A.Efficient
• B.Rapid
• C.Economical
• D.Accurate

Which method is used to separate components of a mixture?

• A.Filtration
• B.Distillation
• C.Chromatography
• D.All of these

The heat of sublimation of potassium is 98 kJ/mol, the heat of dissociation of bromine gas is 192.5 kJ/mol. The ionization energy of K is 414 kJ/mol. The electron affinity of Br is -334.7 kJ/mol and the heat of formation of KBr is -405.8 kJ/mol. Calculate the lattice energy of KBr.

• A.679.3 kJ/mol
• B.589.4 kJ/mol
• C.764.1 kJ/mol
• D.812.6 kJ/mol

Glucose dissolves in water due to?

• A.Ionic bonding
• B.Hydrogen bonding
• C.Covalent bonding
• D.Metallic bonding

A racemic mixture is an equimolar mixture of ?

• A.Enantiomers
• B.Diastereomers
• C.Structural isomers
• D.Geometric isomers

The F-F bond energy is less than Cl-Cl bond energy because of ?

• A.Presence of d-orbitals in fluorine
• B.Large size and low electronegativity
• C.High bond polarity and ionic character
• D.Small size and high electron repulsion

The Universal solvent is _?

• A.Alcohol
• B.Water
• C.Acetone
• D.Benzene

If we dissolve sand into the water, then the mixture is said to be _?

• A.Suspension
• B.Colloid
• C.Solution
• D.Emulsion