HSLC 2024 General Science MCQ Revision

Which one of the following is not a chemical change?

• Digestion of food in our body

• Evaporation of water

• Burning of candle wax

• Cooking food

What is the chemical formula of marble?

• CaCO, Calcium Carbonate

• CaO, Calcium Oxide

FeO2Al ->AlO + 2 Fe; this reaction is an example of ______.

• Double displacement reaction

• Combination reaction

• Displacement reaction

• Decomposition reaction

What happens when dilute hydrochloric acid is added to iron filings?

• No reaction takes place

• Iron salt and water are produced

• Chlorine gas and iron hydroxide are produced

• Hydrogen gas and iron chloride are produced

Which of the following is not a physical change?

• Melting of ice to give water

• Dissolution of salt in air

• Combustion of Liquefied Petroleum Gas (LPG)

• Boiling of water to give water vapour

Which of the following are combination reactions?

• (i) Zn + FeSO -> Zn SO + Fe

• (ii) 4 Al + 3O -> 2AlO

• (iii) MgO + HO -> Mg (OH)

• (iv) 2KClO -> 2KCl + 3O

Which of the following is an endothermic process?

• (i) Dilution of sulphuric acid

• (ii) Sublimation of dry ice

• (iii) Condensation of water vapour

• (iv) Evaporation of water vapour

Which of the following processes involve chemical reactions?

• Heating copper wire in presence of air at high temperature

• Storing of oxygen gas under pressure in a gas cylinder.

• Keeping petrol in a china dish in the open

• Liquefaction of air

Which of the following are exothermic processes?

• (i) Dilution of an acid

• (ii) Evaporation of water

• (iii) Sublimation of camphor

• (iv) Reaction of water with quick lime

4NH(g) + 5O (g) -> 4NO (g) + 6HO (g). This reaction is an example of ------

• Displacement reaction

• Combination reaction

• Redox reaction

• Neutralisation reaction