Cations

Which of the following chemicals can be used to test for cations?

• Aqueous ammonia

• Ammonium nitrate

• Sodium chloride

• Sodium hydroxide

When NaOH (aq) was added to an unknown sample, a white precipitate was formed, insoluble in excess NaOH (aq). Which cation is present?

• Cu²⁺

• Zn²⁺

• Ca²⁺

• Fe²⁺

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When NaOH (aq) was added to an unknown sample, this was observed. Which cation is present?

• Cu²⁺

• Zn²⁺

• Fe²⁺

• Fe³⁺

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When excess aqueous ammonia was added to an unknown sample, this was observed. Which cation is present?

• Cu²⁺

• Zn²⁺

• Ca²⁺

• Fe²⁺

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is a positive ion called?

(a)  

• anion

• cation

• isotope

• covalent

What would be the charge of a potassium ion?

• 0

• -1

• +1

• -7

• +7

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When excess aqueous ammonia was added to an unknown sample, this was observed. Which cation is present?

• Cu²⁺

• Zn²⁺

• Ca²⁺

• Fe²⁺

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When NaOH (aq) was added to an unknown sample, a white precipitate was formed, soluble in excess NaOH (aq), to form a colourless solution. Which cation is present?

• Cu²⁺

• Zn²⁺

• Ca²⁺

• Fe²⁺

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

After warming an unknown sample with sodium hydroxide, gas evolved turned damp red litmus paper blue. Which cation is present?

• ammonium ion

• copper(II) ion

• zinc ion

• iron(III) ion

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When excess sodium hydroxide was added to an unknown sample, this was observed. What is the precipitate formed?

• copper(II) hydroxide

• zinc hydroxide

• iron(III) hydroxide

• iron(II) hydroxide