Chemical Reaction

The diagram shows an experiment where magnesium ribbon is added to dilute acid.

What products are formed in this reaction?

• salt, water, and carbon dioxide gas

• salt and water

• salt and hydrogen gas

• metal hydroxide and hydrogen gas

What gas is given off here?

• oxygen

• carbon dioxide

• hydrogen

• nitrogen

To positive test this gas, we can do . . .

• smell test, because it is odorless

• ignition test that will ignite the lighted splint with a squeaky pop sound

• transfer it to limewater and it will turn the liquid cloudy

• pouring it into the lighted candles and see how it extinguishes the light

Which of the following is an example of a chemical change?

• water freezes to form ice

• sugar dissolves in water

• gasoline burns in a car engine

• a piece of metal expands when it is heated

A change in the shape of an object is an example of _________________.

• a chemical change

• energy

• an endothermic change

• a physical change

a copper penny turning greenish after a few years.

• Chemical Change
• Physical Change

Which of the following is an example of a chemical change?

• rusting of a bicycle
• painting a house
• washing a dog
• tearing up a newspaper

Some hydrochloric acid is added to marble chips in a test tube. The students observed bubbles and fizzing. The gas is ....

• Oxygen gas 
• Carbon dioxide 
• Hydrogen gas 
• nitrogen gas 

Some hydrochloric acid is added to marble chips in a test tube. The marble chips is....

• Lead nitrate 
• Calcium carbonate  
• sodium carbonate 
• calcium oxide  

Some hydrochloric acid is added to marble chips in a test tube. To test for the gas given off from the reaction, I could . . .

• Bubble it through limewater and it will go milky

• do the pop test and it will burn

• Light a taper and it will burn brighter

• note the colour change to yellow