Mia and Ahmed heated a mixture of iron and sulphur using the equipment below. Why did they add mineral wool to the end of the test tube ?

When a mixture of Iron and Sulphur is heated, the sulphur melts and reacts with the iron exothermically to form iron(II) sulphide. The mineral wool plug in the mouth of the test tube prevents sulphur vapour from escaping and possibly catching fire.

Mia and Ahmed heated a mixture of iron and sulphur using the equipment below. What could they do to reduce the risk in this experiment ?

To reduce the risk in the experiment we can follow some steps: Step 1: We must use a Bunsen burner in adult supervision. Step 2: Since it is a highly exothermic reaction so must wear eyeglasses and gloves while doing the experiment. When Iron reacts with sulphur, it forms a new compound called Iron(II)Sulphide ( FeS ) .

E M B I B E

Cambridge Lower Secondary Science Stage 8 : Workbook>Chapter 4 - Elements, Compounds and Mixtures>Exercise 4>Q 4

EASY

Lower Secondary Stage 8

IMPORTANT

Earn 100

What is the formula of Copper Carbonate?

60% studentsanswered this correctly

Important Questions on Elements, Compounds and Mixtures

MEDIUM

Lower Secondary Stage 8

IMPORTANT

Cambridge Lower Secondary Science Stage 8 : Workbook>Chapter 4 - Elements, Compounds and Mixtures>Exercise 4>Q 6

Mia and Ahmed heated a mixture of iron and sulphur using the equipment below.
Question Image

Why did they add mineral wool to the end of the test tube ?

MEDIUM

Lower Secondary Stage 8

IMPORTANT

Cambridge Lower Secondary Science Stage 8 : Workbook>Chapter 4 - Elements, Compounds and Mixtures>Exercise 4>Q 6

Mia and Ahmed heated a mixture of iron and sulphur using the equipment below.
Question Image

What could they do to reduce the risk in this experiment ?

EASY

Lower Secondary Stage 8

IMPORTANT

Cambridge Lower Secondary Science Stage 8 : Workbook>Chapter 4 - Elements, Compounds and Mixtures>Exercise 4>Q 7

Copper sulphate and diamond both form crystals.
The formula of copper sulphate is

{CuSO}_{4} . 5 H_{2} O

The formula of diamond is

C

.
Why is copper sulphate a compound and diamond an element ?

MEDIUM

Lower Secondary Stage 8

IMPORTANT

Cambridge Lower Secondary Science Stage 8 : Workbook>Chapter 4 - Elements, Compounds and Mixtures>Exercise 4>Q 8

Ershad and Pramod were heating copper metal using a Bunsen burner. At the end of the experiment, they noticed that the copper had gone black. Ershad thinks that the metal is covered in shoot but Pramod disagrees.

Explain why Ershad is wrong.

EASY

Lower Secondary Stage 8

IMPORTANT

Cambridge Lower Secondary Science Stage 8 : Workbook>Chapter 4 - Elements, Compounds and Mixtures>Exercise 5>Q 1

Which method you would use to separate salt from a solution of salt water ?
Tick one box.

EASY

Lower Secondary Stage 8

IMPORTANT

Cambridge Lower Secondary Science Stage 8 : Workbook>Chapter 4 - Elements, Compounds and Mixtures>Exercise 5>Q 2

Which method you would use two separate copper turnings (small flakes of copper) from a mixture of iron filings and copper turnings ? Question Image