Chemical Reactions - End of Topic Quiz

Which of the following could be signs that a chemical reaction is taking place?

Select all the correct answers.

• Colour change

• Fizzing or bubbling

• Change in temperature

potassium iodide is poured into a beaker of lead nitrate. Yellow lead iodide is formed  in a solution of potassium nitrate.
Select the two reactants in this experiment.

• Potassium Iodide

• Lead Nitrate

• Lead Iodide

• Potassium Nitrate

potassium iodide is poured into a beaker of lead nitrate. Yellow lead iodide is formed  in a solution of potassium nitrate.
Select the two products in this experiment.

• Potassium Iodide

• Lead Nitrate

• Lead Iodide

• Potassium Nitrate

All reactions must obey the law of ____________ of mass

The law of conservation of mass says that the mass of reactants is always ____________ the mass of the products.

• greater than

• less than

• the same as

Adrian heated 1.24g of copper carbonate strongly.
The chemical reaction, which took place, is represented by the equation:

Copper Carbonate --> Copper Oxide + Carbon Dioxide

He weighed his products and found that its mass was 0.80g.
Why did the Adrian find a decrease in mass in this experiment?

• The Copper Oxide is a gas which could escape.

• Carbon Dioxide is a gas which could escape.

• The Copper Oxide is a solid which could escape.

• Carbon Dioxide is a solid which could escape.

How does this diagram show conservation of mass?

In this reaction, Copper Carbonate is burned in a crucible. The name given to the chemicals at the start of a reaction is the _________

In this reaction, Copper Carbonate is burned in a crucible. Copper Oxide is formed. The name given to the chemicals produced in a reaction is ________

What is the mass of Copper Carbonate in the crucible?

• 0.44g

• 1.24g

• 0.80g