CHEMISTRY CONTEST JUNIOR CLASS 2024

Calcium reacts with hydrochloric acid to form the salt, calcium chloride and another product.

calcium + hydrochloric acid → calcium chloride + ___________________

What is the unknown product?

• Water

• Oxygen

• Hydrogen

• Carbon (IV) oxide

Indicators are used during a titration to observe the end point.

Different indicators turn different colours in acids and alkalis.

Which indicator displays the correct colour in each solution?

• Methly orange

• Universal indicator

• Litmus

• Phenolphthalein

The diagram above represents a sample of air:

What correctly describes this sample of air

• an element

• a compound

• a mixture of elements

• a mixture of compounds

Which of these describes a solution with a pH value of 9?

• Strongly acidic

• Strongly alkaline

• Weakly acidic

• Weakly alkaline

The hazard symbol shown in the figure above is used on containers of sodium.

What is the meaning of this hazard symbol?

• corrosive

• flammable

• oxidising

• toxic

Which technique is the best for separating pure water from a solution of sodium chloride?

• Chromatography

• Crystallization

• Distillation

• Filtration

Which of the following is not an example of physical change?

• evaporation

• condensation

• boiling

• rusting

Which of the following statement is NOT a characteristic of Temporary chemical change?

• A new substance is formed

• The change can be reversed

• There is change in mass

• They are not accompanied by net heat change

Which of the following is NOT a property of Acid?

• Have bitter taste

• Have pH values below 7

• reacts with carbonates to form salt, carbon (IV) oxide and water

• Turn methly orange pink