Topic 2 Chemical Changes

Question 1

What safety precautions should you take when using a Bunsen?

Answer 1

Tie long hair back.
Roll up sleeves.
Tuck in your tie.
Put on safety goggles.
Remove any flammable liquids.
Don’t leave the gas tap on for too long before lighting the Bunsen.

Question 2

What must you do to light a Bunsen Burner?

Answer 2

Attach the rubber tubing to the gas tap.
Move the collar until the air hole is ⅓ open.
Light a wooden splint and hold it above the chimney.
Turn on the gas by moving the gas tap.

Question 3

What is the colour of the flame when the air hole is ⅓ open?

Answer 3

Yellow tinged blue.

Question 4

What is the colour of the flame when the air hole is fully open?

Answer 4

Two toned blue.

Question 5

What is the inner cone made out of?

Answer 5

Cold, unburnt gas.

Question 6

Where is the hottest part of the flame?

Answer 6

Slightly above the tip of the inner cone.

Question 7

What are three observations of the flame when the air hole is fully open?

Answer 7

Roaring.
Two toned blue.
Hard to see.

Question 8

What are three observations of the flame when the air hole is fully closed?

Answer 8

Quiet.
Yellow / orange.
Easy to see.

Question 9

A chemical labelled ‘X’ is put over a lit Bunsen Burner and the flame turns brick red. What chemical is ‘X’ and what metal is present?

Answer 9

‘X’ is calcium chloride and the metal present is calcium.

Question 10

A chemical labelled ‘A’ is put over a lit Bunsen Burner and the flame turns