Gases in reactions

Question 1

What happens when you burn an element in air?

Answer 1

It reacts with oxygen to form an oxide

Question 2

Magnesium

Answer 2

Magnesium burns with a bright white flame in air and the white powder which is formed is called magnesium oxide. This is slightly alkaline when dissolved in water.

Question 3

Hydrogen

Answer 3

Hydrogen burns very easily in oxygen and can be explosive. it produces an orange/yellow flame and the only product is water (as vapor).

Question 4

What is the combustion of hydrogen gas used for

Answer 4

A test for hydrogen gas –> squeaky pop

Question 5

Sulfur

Answer 5

Sulfur burns in air or oxygen with a pale blue flame and produces sulfur dioxide. This is acidic when dissolved in water.

Question 6

Thermal decomposition of metal carbonates produces CO2

Answer 6

1) If you heat a metal carbonate, you get carbon dioxide and metal oxide.
2) This is an example of thermal decomposition.
3) Copper (II) carbonate is a green powder that will easily decompose to form carbon dioxide and copper (II) oxide when you heat it.

Question 7

How to show that decomposition of copper (II) carbonate produces CO2.

Answer 7

1) Heat copper (II) carbonate then collect the gas given off in a test tube.
2) The gas that is collected can then be tested to see if it is CO2 by bubbling it through limewater.