Chapter 13: Laboratory and Practical SkillsMCQs with Answers
All 24 MCQs of 9th Class Chemistry Chapter 13, Laboratory and Practical Skills, with answers and the reason each option is right or wrong: the 8 textbook exercise MCQs plus 16 more board-style MCQs. Punjab Board new syllabus.
Try each one first: tap an option to check it, then read the reasoning and why the others are wrong.
A note about the questions
The wording follows published solved exercises and every answer was re-checked by hand, so the wording or the order of options may differ slightly from your print.
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Set A: Textbook exercise 8 MCQs
The multiple-choice questions at the end of Chapter 13 in your book, in the book's option order.
Q13.1Lab Rules and Conduct
Safety in the chemistry laboratory is:
Answer(d) a shared responsibility
Step by step
Students follow rules; teachers supervise; lab staff maintain equipment.
Why the others are wrong
(a) teachers and staff are responsible too.
(b) not one person.
(c) not one person.
Remember
Everyone in the room is responsible.
Q13.2Lab Rules and Conduct
Accidents often result from:
Answer(d) all of the above
Step by step
Each option is a real cause.
Why the others are wrong
(a) true, but not the only cause.
(b) true, but not the only cause.
(c) true, but not the only cause.
Remember
All three are true → all of the above.
Q13.3Hazard Signs
The label "Warning" on a chemical bottle signifies:
Answer(a) that the chemical can cause less serious injury
Step by step
Danger = severe.
Warning = less severe.
Why the others are wrong
(b) that is the meaning of "Danger".
(c) true of every chemical, not what "Warning" specifically signifies.
(d) not the meaning of the signal word.
Remember
Danger > Warning.
Q13.4Hazard Signs
The label "Corrosive" on a chemical bottle indicates:
Answer(c) that its contact destroys living tissue
Step by step
Corrosive: acids like HF, H₂SO₄; caustic alkalies like NaOH.
Why the others are wrong
(a) that is the oxidising sign (flame over a circle).
(b) Wrong.
(d) that is the explosive sign.
Remember
Corrode = eat away.
Q13.5Corrosive and Toxic Hazards
Example of highly toxic chemical:
Answer(c) Potassium cyanide
Step by step
Cyanides (KCN, HCN) are among the most toxic lab chemicals.
Why the others are wrong
(a) mainly flammable.
(b) corrosive when glacial.
(d) an oxidiser, harmful but not highly toxic.
Remember
Cyanide = poison.
Q13.6Reactive, Radiation and Asphyxiation Hazards
Example of self-reactive chemical:
Answer(c) Picric acid
Step by step
Self-reactive = reacts by itself.
Potassium needs water or air.
Why the others are wrong
(a) very reactive, but with water or air, not by itself.
(b) toxic and corrosive, not self-reactive.
(d) flammable, not self-reactive.
Remember
Picric acid: explosive on its own.
Q13.7Corrosive and Toxic Hazards
When diluting an acid with water:
Answer(c) always add acid to water
Step by step
Acid → water, slowly, stirring.
Why the others are wrong
(a) it must be slow.
(b) stir to spread the heat.
(d) dangerous spattering.
Remember
"Do what you oughta, add acid to water."
Q13.8PPE and Emergencies
What should you do in case of a fire drill in the lab.?
Answer(c) close gas valves and turn off all equipments
Step by step
Stop sources: gas off, power off.
Then evacuate calmly.
Why the others are wrong
(a) the shower is for burns and splashes, not drills.
(b) absurd and dangerous.
(d) carrying chemicals adds danger.
Remember
Shut off, then get out.
Set B: More MCQs from this chapter 16 MCQs
Extra questions on the same ideas, of the kind set in board papers and class tests.
QB1Lab Rules and Conduct
If it is necessary to smell a gas in the laboratory, you should:
Answer(a) waft the fumes towards your nose
Step by step
Hold the tube away; wave a hand over its mouth towards the nose.
Why the others are wrong
(b) a strong dose can harm the nose and lungs.
(c) never taste anything in the lab.
(d) heating makes more vapour.
Remember
Waft, never sniff.
QB2Corrosive and Toxic Hazards
A fume cupboard (fume hood) is used for:
Answer(b) reactions that give toxic or corrosive vapours
Step by step
Fan draws air in at the front and out through a duct.
Why the others are wrong
(a) no food in the lab at all.
(c) that is the sink.
(d) air flow disturbs a balance.
Remember
Fumes → fume cupboard.
QB3Flammable and Explosive Hazards
Flammable chemicals are those which have a flashpoint:
Answer(b) around room temperature
Step by step
Flashpoint = lowest temperature at which vapour ignites.
Why the others are wrong
(a) that would make them hard to ignite.
(c) impossible.
(d) Wrong.
Remember
Low flashpoint = catches fire easily.
QB4Flammable and Explosive Hazards
Which of these is a flammable compound?
Answer(d) Acetone
Step by step
Keep acetone away from flames and heat.
Why the others are wrong
(a) does not burn.
(b) Wrong.
(c) Wrong.
Remember
Organic solvents burn.
QB5Corrosive and Toxic Hazards
When working with corrosive chemicals one should wear:
Answer(b) splash goggles and a face shield
Step by step
Goggles seal; glasses do not.
Why the others are wrong
(a) splashes enter from the sides.
(c) Wrong.
(d) Wrong.
Remember
Corrosive → goggles + shield.
QB6Reactive, Radiation and Asphyxiation Hazards
Which of the following is an asphyxiant?
Answer(a) Carbon monoxide
Step by step
Asphyxiant → suffocation.
Why the others are wrong
(b) a harmless salt.
(c) a sugar.
(d) chalk.
Remember
Gases that steal oxygen.
QB7Reactive, Radiation and Asphyxiation Hazards
Exposure to radiation is monitored by wearing:
Answer(c) badges (dosimeters)
Step by step
Badge darkens / counts with dose.
Why the others are wrong
(a) temperature.
(b) pressure.
(d) acidity.
Remember
Radiation → badge.
QB8Corrosive and Toxic Hazards
Acid and alkali waste is disposed of by:
Answer(b) first neutralising it, then sewer disposal
Step by step
Acid + base → salt + water, then flush.
Why the others are wrong
(a) corrodes pipes and harms the environment.
(c) Wrong.
(d) Wrong.
Remember
Neutralise first.
QB9Flammable and Explosive Hazards
Which of these is an explosive chemical named in the book?
Answer(a) Picric acid
Step by step
Explosives release pressure, gas and heat on sudden shock.
Why the others are wrong
(b) Wrong.
(c) Wrong.
(d) Wrong.
Remember
Picric, peroxide, nitro → explosive.
QB10Corrosive and Toxic Hazards
Which of these is a toxic chemical?
Answer(a) Mercury
Step by step
Clean up mercury spills with a kit, never a vacuum cleaner.
Why the others are wrong
(b) Wrong.
(c) table sugar.
(d) Wrong.
Remember
Hg = toxic.
QB11Hazard Signs
A hazard sign showing a skull and crossbones means:
