RP4: Investigating how rate changes with temperature

What is the result when barium ions react with NaOH dropwise until in excess? (1)

No visible change (NVC)

What is observed when calcium ions react with NaOH dropwise until in excess? (1)

Slight white precipitate

How does magnesium ion react with NaOH dropwise until in excess? (2)

- Slight white precipitate.

- White precipitate in excess.

What is the result when strontium ions react with NaOH dropwise until in excess? (1)

Slight white precipitate

What is the result when barium ions react with dilute H₂SO₄ dropwise until in excess? (1)

White precipitate

How does calcium ion react with dilute H₂SO₄ dropwise until in excess? (1)

Slight white precipitate

What is the result when magnesium ions react with dilute H₂SO₄ dropwise until in excess? (2)

- Slight white precipitate.

- Colourless solution in excess.

How does strontium ion react with dilute H₂SO₄ dropwise until in excess? (1)

White precipitate

How can ammonium ions be identified using NaOH? (2)

1. Gently heat.

2. Hold damp red litmus paper over the gas; ammonia gas is produced, turning litmus blue.

How can hydroxide ions be identified using indicator paper? (1)

Turns red litmus paper or universal indicator paper blue

What is the test for carbonate ions? (3)

1. Add HCl.

2. Test the gas produced with calcium hydroxide solution (limewater)

3. Effervescence occurs, CO₂ gas is produced, and limewater turns cloudy

How can sulfate ions be identified? (2)

1. Add HCl followed by barium chloride

2. White precipitate forms

How do chloride ions in solution react with silver nitrate? (1)

White precipitate forms

What happens when dilute ammonia is added to chloride precipitate from silver nitrate? (1)

Precipitate dissolves

How do bromide ions in solution react with silver nitrate? (1)

Cream precipitate forms

What happens when concentrated ammonia is added to bromide precipitate from silver nitrate? (1)

Precipitate dissolves

How do iodide ions in solution react with silver nitrate? (1)

Pale yellow precipitate forms

What happens when concentrated ammonia is added to iodide precipitate from silver nitrate? (1)

No visible change

What is the result when solid chloride reacts with concentrated H₂SO₄? (2)

- Effervescence.

- Damp blue litmus paper turns red (HCl produced).

How does solid bromide react with concentrated H₂SO₄? (3)

- Effervescence.

- Brown gas (Br₂) is produced.

- Solution turns red/brown.

What happens when gas from solid bromide reacting with H₂SO₄ is tested with acidified potassium dichromate solution? (1)

Turns solution orange

How does solid iodide react with concentrated H₂SO₄? (3)

- Brown gas (Br₂) is produced.

- Solution turns red/brown.

- Paper dipped in lead nitrate turns black.