IGCSE Chemistry

What is the oxidation number of sulfur in H₂SO₄?

• 0

• +1

• +4

• +6

What happens to the oxidising agent in an oxidation-reduction reaction?

• It is oxidised as it gains electrons.

• It is oxidised as it loses electrons.

• It is reduced as it gains electrons.

• It is reduced as it loses electrons.

Which of the following half reactions correctly represents a reduction half reaction?

• Fe →Fe²⁺ + 2e^-

• Pb⁴⁺ + 2e^- →Pb²⁺

• 2O^-2 →O₂ + 4e^-

• Fe + 3e^- →Fe³⁺

Which of the following represents oxidation?

• C → CH₄

• Fe³⁺ → Fe²⁺

• Cl₂ → 2Cl^-

• Zn → ZnO

Tags

NGSS.HS-PS1-2

In the reaction Zn + 2HCl --> ZnCl₂ + H₂

which element, if any, is oxidized?

• Zinc

• Hydrogen

• Chlorine

• None

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which statement is true:
Mg → Mg²⁺ + 2e^–

• Mg gains 2 electrons

• Mg_²⁺ loses 2 electrons

• Mg loses 1 electron

• Mg loses 2 electrons

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Complete the general equation:

Metal + Acid ->

• Salt + Water

• Salt + Hydrogen

• Salt

Tags

NGSS.MS-PS1-5

Complete the general equation:

Metal + Water ->

• Salt + Water

• Metal Hydroxide + Hydrogen

• Metal hydroxide + Water

• Salt + Hydrogen

Tags

NGSS.MS-PS1-5

Complete the equation:

Potassium + Water ->

• Potassium Hydroxide + Hydrogen

• Potassium Chloride + Hydrogen

• Potassium Hydroxide + Water

• Nitric Potassium + Hydrogen

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Will a displacement reaction occur?

• Yes

• No