Homework Practice

Printable assignment

Mixtures in Daily Life: Solubility, Safety and Smart Experiments

Section A: Solubility and Daily Practices

Question 1mcq

A solubility graph shows how solubility changes with:

A.Sound

B.Colour only

C.Container shape

D.Temperature

Question 2mcq

If solubility of a salt decreases on cooling, crystals may form because:

A.The solvent becomes a metal

B.The solute disappears

C.The salt becomes magnetic

D.The solution can no longer hold all dissolved solute

Question 3mcq

Winnowing separates grain from husk using:

A.Centrifuge

B.Boiling point

C.Wind

D.Chromatography

Question 4mcq

Sieving works when components differ in:

A.Smell only

B.Solubility always

C.Boiling point only

D.Particle size

Question 5mcq

Evaporation is commonly used to obtain:

A.Salt from seawater

B.Dyes from ink

C.Cream from milk

D.Iron from sulphur

Question 6mcq

A sudden drop in temperature can help crystallisation because:

A.All mixtures become elements

B.Solubility may decrease and excess solute separates

C.Solute becomes invisible permanently

D.Solvent stops being matter

Section B: Laboratory Inquiry and Safe Apparatus

Question 7mcq

When heating a solution, students should:

A.Hold test tube mouth toward face

B.Mix unknown chemicals randomly

C.Use proper apparatus and avoid direct contact with hot equipment

D.Taste the hot solution

Question 8mcq

Why should goggles be used during some separation activities?

A.To stop evaporation

B.To protect eyes from splashes or particles

C.To make solute heavier

D.To increase concentration

Question 9mcq

A model distillation setup should clearly show:

A.A magnet for every mixture

B.Only decorative labels

C.No path for vapour

D.Evaporation and condensation parts

Question 10mcq

A paperfuge model demonstrates separation by:

A.Dissolving

B.Spinning

C.Sublimation

D.Boiling

Question 11mcq

A good experiment plan should include:

A.Only final answer

B.Hypothesis, steps, observations and conclusion

C.No variables

D.Only a drawing

Question 12mcq

To compare filtration and sedimentation fairly, students should:

A.Use similar muddy water samples

B.Avoid recording time

C.Use random mixtures each time

D.Change all variables together