All Free Chemistry MCQs with Answers

• A. NaCl
• B. MgCl2
• C. KCl
• D. AlCl3

Explanation: The correct answer is KCl because it forms the most ionic bond among the options provided.

• A. Ionization energy depends upon the magnitude of nuclear charge
• B. Ionization energy depends upon the atomic radius
• C. Ionization energy depends upon the shielding effect
• D. Ionization energy does not depend upon the penetration effect of the inner orbital

Explanation: Option D is the correct answer because it incorrectly states that ionization energy does not depend on the penetration effect.

• A. HBO2
• B. HFO2
• C. H3PO3
• D. HBrO2

Explanation: HBrO2(aq) is bromous acid and HIO2(aq) is iodous acid. Like many of the oxyacids, the molecules of HBrO2 (hydrogen bromite) and HIO2…

• A. Charge on nucleus
• B. Screening effect
• C. Electronic configuration
• D. All of the above

Explanation: Ionization energy, also called ionization potential is the amount of energy required to remove an electron from an isolated atom or…

• A. XYZ
• B. XZY
• C. YXZ
• D. ZXY

Explanation: In a given period of the periodic table, the nature of oxides changes from basic to amphoteric to acidic as you move from left to right.

• A. Sc3+
• B. Li2+
• C. Ba3+
• D. Na+

Explanation: In aqueous medium, due to extremely large hydration energy (energy evolved when a substance is hydrolysed), in aqueous medium, Li+ is more…

• A. Yellow Colored solution
• B. Greenish Colored solution
• C. Bluish Colored solution
• D. Colorless solution

Explanation: Chlorine gas dissolves in water, forming a greenish solution called perchloric acid.

• A. Phosphoruss (iii) oxide
• B. Phosphoruss (v) oxide
• C. Phosphorus (ii) oxide
• D. Both (A) & (B)

Explanation: When white phosphorus burns in air, it undergoes a slow combustion reaction to form phosphorus (I) oxide, which is also known as…

• A. Mo(ii)
• B. Mo(iii)
• C. Mo(v)
• D. Mo(vi)

Explanation: Students should learn the Mo(ii) has the lowest oxidation state and highest electronegativity.Compared to the other given oxidation states…

• A. Sb3+
• B. Bi3+
• C. Sn3+
• D. Fe3+

Explanation: This is a fact Boron does not have a d orbital to stabilize its charge and thus is unstable as a cation in aqueous solution.This is a fact…

• A. CrO> Cr2O3> CrO3
• B. CrO3> Cr2O3>CrO
• C. Cr2O3 >CrO>CrO3
• D. CrO3>CrO> Cr2O3

Explanation: The increasing acidic strength is in this order of oxidation state; Cr3+ > Cr2+ > Cr+1 As increasing oxidation state increases the acid…

• A. ClO3
• B. ClO2
• C. Cl2 O7
• D. CI2 O7

Explanation: Anhydride literally means 'without water. It can be defined as the chemical compound formed by eliminating water from another compound…

• A. Increase
• B. Decrease
• C. Increase then decrease
• D. Decrease then increase

Explanation: Ionic radius increases as you move from top to bottom on the periodic table.

• A. Cs
• B. Li
• C. He
• D. I

Explanation: Helium (He) has the highest first ionization energy. This means that it requires the most energy to remove an electron from a helium atom…

• A. Si and Al
• B. Ca and Mg
• C. B and Ar
• D. B and Al

Explanation: Silicon (Si) and Aluminum (Al) are the two most abundant elements in the Earth's crust.

• A. 1 M HF
• B. 1 M HCL
• C. 1 m CH3COOH
• D. 1 M NaOH

Explanation: As we know that lower the pH, stronger the acid and greater the no of hydrogen ions in a solution.

• A. 3
• B. -3
• C. - antilog [3]
• D. 10^-3

Explanation: pH is defined as the negative logarithm of the hydrogen ion concentration [H+].

• A. Mg(OH)2
• B. MgSO4
• C. Ca(OH)2
• D. CaSO4

Explanation: Milk of magnesia is a suspension of magnesium hydroxide, with the chemical formula Mg(OH)2.

• A. 0.0001 mol/L
• B. -4
• C. 10-4 mol/L
• D. 10-10

Explanation: To determine the concentration of nitric acid in moles per liter with a pH of 4, we apply the formula: pH = -log[H+].

• A. 10−5
• B. 5
• C. 10−9
• D. 9

Explanation: As we know that,pH+pOH=14pOH=14-9=5Also, pOH=log[OH-][OH-]=antilog(pOH)[OH]=antilog (5)[OH]=10-5