Gases

Question 1

how do you test for oxygen?

Answer 1

a glowing wooden splint relights in a test tube of oxygen

Question 2

how do you produce co2? and what is the test for it?

Answer 2

• react calcium carbonate (marble chips) and HCL

- bubble it through lime water and if CO2 is present the lime water will turn purple.

Question 3

what gasses are present in air and what percent?

Answer 3

• 78% nitrogen
• 21% oxygen
• 1% argon
• 0.04% CO2

Question 4

what experiment can be used to work out the % oxygen in air?

Answer 4

the experiment with 2 gas syringes and copper flakes in the middle and the vopper is heated whilst the air is passed through the copper. at the end re measure the gas volume and it should only be 80% of the original, as the oxygen has reacted with the copper.

Question 5

how to make hydrogen?

Answer 5

HCL and Mg

Question 6

how to make oxygen?

Answer 6

hydrogen peroxide > water + Oxygen
(in presence of manganese oxide)
2H^(2)O^(2) > H^(2)O + O^(2)

Question 7

what can CO2 be used for?

Answer 7

• carbonating drinks- soluble

- in fire extinguishers- dense (suffocates)

Question 8

how do you test for ammonia?

Answer 8

makes damp red litmus paper turn blue.

Question 9

how do you test for chlorine?

Answer 9

makes damp blue litmus paper turn red then bleaches it white.