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 general knowledge science & technology

What is O3 (O followed by the number 3, usually shown in sub-script)

  1. Oxygen

  2. Oxytone

  3. Oxford

  4. Ozone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

O3 represents ozone - a molecule consisting of three oxygen atoms. It is not the same as oxygen (O2), oxytone (a linguistic term), Oxford (a city), or Oxford University. Ozone plays a crucial role in the atmosphere, both as a protective layer in the stratosphere and as a pollutant at ground level.

Multiple choice

Which of the following statements is/are incorrect?

  1. The central metal atom shows +4 oxidation states in potassium chromate and potassium dichromate.
  2. Limonite and sphalerite are ores of zinc.
  3. Zinc oxide is known as white lead with the formula (PbCO3)2.Pb(OH)2 and is used as a whitening material.

  1. Only 1

  2. Only 2

  3. Only 3

  4. 1 and 2

  5. 2 and 3
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Correct answer. Limonite (Fe2O3.3H2O) is the ore of iron and sphalerite is the ore of zinc. Zinc oxide is an inorganic compound with the formula ZnO. ZnO is a white powder that is insoluble in water, and it is widely used as an additive in numerous materials and products including rubbers, plastics, ceramics, glass, cement, etc. White lead (PbCO3)2•Pb(OH)2 is a complex chemical compound, containing both a carbonate and a hydroxide portion and occurs naturally as a mineral for lead. White lead compounds were used as pigmenting materials like cement, lubricants, etc. But due to its toxicity, they are not used frequently.

Multiple choice

What is the formula for ozone?

  1. O

  2. O2

  3. O3

  4. O4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ozone is a molecule composed of three oxygen atoms (O3). It differs from the normal oxygen we breathe (O2, dioxygen) and is formed when UV radiation splits O2 molecules and they recombine with other oxygen atoms. O and O4 are not stable forms of oxygen in normal conditions.

Multiple choice

K2Cr2O7 is

  1. Potassium dichromate

  2. Potassium triacetates

  3. Potassium chromate

  4. Chromic acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

K2Cr2O7 is the chemical formula for potassium dichromate. The compound contains two potassium (K) atoms and two chromium (Cr) atoms in a +6 oxidation state, with seven oxygen (O) atoms. Potassium triacetates would be K(C2H3O2)3, potassium chromate is K2CrO4, and chromic acid is H2CrO4.