test for gases

Question 1

the smell of ammonia gas

Answer 1

colorless and pungent

Question 2

Test for ammonia gas

Answer 2

Test with a moist piece of red litmus paper

Question 3

Observation for ammonia gas

Answer 3

Moist red litmus paper turns blue

Question 4

the smell of Carbon dioxide, CO2

Answer 4

colorless and odorless

Question 5

Test for Carbon dioxide, CO2

Answer 5

Bubble the gas through limewater, Ca(OH)2

Question 6

Observation for Carbon dioxide, CO2

Answer 6

A white precipitate (CaCO3) is formed

Question 7

the smell of Chlorine, Cl2

Answer 7

greenish-yellow, pungent

Question 8

Test for Chlorine, Cl2

Answer 8

Test with a moist piece of blue litmus paper

Question 9

Observation for Chlorine, Cl2

Answer 9

Blue litmus paper first turns red and then

bleached

Question 10

the smell of Hydrogen, H2

Answer 10

colorless, odorless

Question 11

Test for Hydrogen, H2

Answer 11

Place a lighted splint near the gas

Question 12

Observation for Hydrogen, H2

Answer 12

Gas extinguishes lighted splint with a “pop” sound

Question 13

the smell of Oxygen, O2

Answer 13

colorless, odorless

Question 14

Test for Oxygen, O2

Answer 14

Place a glowing splint near the gas

Question 15

Observation for Oxygen, O2

Answer 15

Gas reignites glowing splint

Question 16

the smell of Sulfur dioxide, SO2

Answer 16

colorless,

pungent

Question 17

Test for Sulfur dioxide, SO2

Answer 17

Bubble the gas through a solution of acidified potassium
dichromate(VI), K2Cr2O7
.
Alternative: Bubble the gas through a solution of acidified
potassium manganate(VII), KMnO4
.
Recall: SO2 is a reducing agent! Redox reaction occurs.

Question 18

Observation for Sulfur dioxide, SO2

Answer 18

Acidified potassium dichromate (VI)
turns from orange to green
.
Acidified potassium manganate (VII)
turns from purple to colorless