All Free Chemistry MCQs with Answers

• A. Large radius and low charge density
• B. Small radius and low charge density
• C. Large radius and high charge density
• D. Small radius and high charge density

Explanation: Correct, as lithium has the smallest atomic size in the alkali metal group, leading to high charge density, which makes it behave…

• A. decreases
• B. gradually increases then decreases
• C. increases
• D. remains same

Explanation: The metallic character of alkaline earth metals increases down the group.As you move down Group 2 in the periodic table, elements like…

• A. Get4 < Pb+4 < Sn+4
• B. Ge+4 < Snt4 < Pb+4
• C. Get4 > Pb+4 > Sn+4
• D. Ge+4 > Sn+4 > Pb+4

Explanation: The stability order of M+4 cations generally depends on factors like the size of the cation, its effective nuclear charge, and the…

• A. Beryllium
• B. Lithium
• C. Magnesium
• D. Potassium

Explanation: Potassium reacts with oxygen to form potassium superoxide (KO2 ), especially in an oxygen-rich environment.

• A. Ca(OH)2
• B. LiOH
• C. Mg(OH)2
• D. NaOH

Explanation: The strength of a base in the hydroxide form typically increases down a group in the periodic table due to the increasing size of the…

• A. K
• B. Li
• C. Na
• D. Rb

Explanation: The normal oxide of lithium is lithium oxide (Li₂O). It is formed when lithium reacts with oxygen in a stoichiometric ratio.

• A. Al
• B. Mg
• C. Na
• D. Si

Explanation: Al forms Al2O3 after reacting with oxygen which acts as a protective layer against further corrosion.

• A. Cu (Copper)
• B. Na (Sodium)
• C. Fe (Iron)
• D. Al (Aluminum)

Explanation: Sodium is a highly reactive alkali metal. It reacts vigorously with water, producing hydrogen gas and heat.

• A. Na2 O and NO2
• B. NaNO2 and O2
• C. Na, NO2 and O2
• D. Na2 O, NO2 and O1

Explanation: This is correct. Sodium nitrate decomposes into sodium nitrite and oxygen gas.

• A. Good conductor
• B. Non-conductor
• C. Semi-conductor
• D. None of these

Explanation: Diamond has a strong network of covalent bonds, with no free electrons.

• A. BeO
• B. MgO
• C. CaO
• D. BaO

Explanation: BaO) - Correct: Barium oxide dissolves most easily in water as it has the lowest lattice energy and the most ionic character among these…

• A. Increases
• B. Decreases
• C. Remain unchanged
• D. Has irregular trend

Explanation: (Increases) - Correct: Down the group, metallic reactivity increases because atomic size increases, and ionization energy decreases…

• A. More
• B. Less
• C. Equal to
• D. Two times more

Explanation: More) - Correct: The solutions of Group IIA hydroxides become more basic down the group due to increased solubility and higher OH⁻ ion…

• A. OH⁻
• B. H₂O
• C. O²⁻
• D. M²⁺

Explanation: OH⁻) - Correct: Hydroxide ion (OH⁻) is the base formed in solution

• A. Be + 2H₂O → H₂ + Be(OH)₂
• B. Mg + 2H₂O → H₂ + MgO
• C. Ca + 2H₂O → H₂ + Ca(OH)₂
• D. Ba + 2H₂O → H₂ + Ba(OH)₂

Explanation: Be + 2H₂O → H₂ + Be(OH)₂) - Correct: This reaction is not possible because Be does not react with water under normal conditions.

• A. 20
• B. 30
• C. 100
• D. 10

Explanation: The correct answer is Option C: 100. Perhydrol, also known as hydrogen peroxide (H2O2), has a volume strength of 100, indicating a highly…

• A. NaHCO3
• B. NaHSO3
• C. Na2SO3
• D. NaHSO4

Explanation: The correct answer is Option C: Na2SO3. Sodium carbonate reacts with SO2 in aqueous solution to give Na2SO3.

• A. K2CO3 is more soluble
• B. K2CO3 is less soluble
• C. KHCO3 is more soluble than NaHCO3
• D. KHCO3 is less soluble than NaHCO3

Explanation: The Solvay process relies on the precipitation of bicarbonates. In the case of sodium, NaHCO3 is less soluble and precipitates out easily…

• A. Be++ < Mg++ < Ca++ < Ba++ < Si++
• B. Si++ < Ba++ < Ca++ < Mg++ < Be++
• C. Ba++ < Si++ < Ca++ < Mg++ < Be++
• D. Ba++ < Si++ < Mg++ < Ca++ < Be++

Explanation: Hydration energy is inversely related to the size of the cation. Smaller cations have higher hydration energy because they can attract…

• A. Ionization energy
• B. Solubility of their hydroxides
• C. Solubility of their sulphates
• D. Electronegativity

Explanation: The correct answer is Option B: Solubility of their hydroxides. The property of alkaline earth metals that increases with their atomic…