Chemistry

Oxidation States and Oxides

308 Questions

Oxidation states represent the degree of oxidation of an atom in a chemical compound. This topic covers calculating valency, classifying oxides as acidic or basic, and understanding thermal decomposition. These concepts are frequently tested in chemistry sections across multiple competitive examination platforms.

calculating oxidation statesclassification of oxidesvalency determinationthermal decompositionstability of metal oxides

Oxidation States and Oxides Questions

Multiple choice

Dichromate ion in acidic medium oxidise stannous ion as: xSn2+ + yCr2O72– + zH+ → aSn4+ + bCr3+ + cH2O for the above reaction,

  1. the value of x : y = 1 : 3

  2. the value of x + y + z = 18

  3. a : b = 2 : 3

  4. the value of z – c = 5

  5. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The reaction can be given as: Reduction half→Cr2O72– + 14H+ + 6e →  2Cr3+ + 7H2O Oxidation half→[Sn2+ – 2e → Sn4+]*3 So the balanced chemical equation is 3Sn2+ + Cr2O72– +14H+ = 3Sn4+ + 2Cr3+ + 7H2O therefore, x + y + z = 18, hence this is a correct option.  

Multiple choice

Correct order of acidic character of oxides of manganese is

  1. MnO < MnO2 < Mn2O3 < Mn2O7

  2. Mn2O7 < Mn2O3 < MnO2 < MnO

  3. MnO < Mn2O3 < MnO2 < Mn2O7

  4. MnO < Mn2O3 < Mn2O7 < MnO2

  5. Mn2O3 < MnO2 < MnO < Mn2O7
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Correct order of acidic behaviour is Mangnese(II) oxide < Manganese(III) oxide < Manganese(IV) oxide < Manganese(VII) oxide.

Multiple choice

The symbol of 'Oxygen element' is

  1. Ox

  2. O

  3. Oy

  4. None of these.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The chemical symbol for oxygen is 'O', derived from its Latin name 'Oxygenium'. 'Ox' and 'Oy' are not valid chemical symbols for any element.

Multiple choice

Oxygen is

  1. diamagnetic

  2. paramagnetic

  3. ferromagnetic

  4. ferrimagnetic
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ans : 2.

Multiple choice

Sulphur dioxide is ______.

  1. basic oxide

  2. acidic oxide

  3. neutral oxide

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sulphur dioxide (SO2) is classified as an acidic oxide because it reacts with water to form sulfurous acid (H2SO3). Acidic oxides are non-metal oxides that form acids when dissolved in water, unlike basic oxides which form bases.