20 questions-chemical analysis

Question 1

how can we test for hydrogen gas

Answer 1

a lit splint squeaky pop

Question 2

how can we test for oxygen gas

Answer 2

glowing splint relights

Question 3

how can we test for carbon dioxide gas

Answer 3

limewater turns cloudy

Question 4

how can we test for chlorine gas

Answer 4

litimus paper bleaches

Question 5

how do u calculate rf value of a substance

Answer 5

distance moved by substance/distance moved by solvent

Question 6

whats the mobile phase in chromotography

Answer 6

water since its moving

Question 7

whats the stationary phase in chromotography

Answer 7

the paper since it doesnt move

Question 8

whats a pure substance

Answer 8

substance made of a single element or compound

Question 9

whats a formulation

Answer 9

a mixture to make a useful product

Question 10

how can u test if a substance is pure

Answer 10

itll have a specific melting or boiling point

Question 11

give 4 advantages of instumental methods of analysis

Answer 11

fast,sensitive,accurate and can be used on small samples

Question 12

what typa substances can be analysed using flame tests

Answer 12

solutions containing metal ions

Question 13

what flame colour is produced when copper chloride is used in a fame test

Answer 13

green

Question 14

whats a precipitaate

Answer 14

a solid formed when 2 solutions are mixed

Question 15

what colour is a copper hydroxide precipitate

Answer 15

blue

Question 16

how can a sulfate be idenitified

Answer 16

add dilute hcl and barium chloride solution then look for a white precipitate of barium sulfate

Question 17

what colour is silver bromide precipitate

Answer 17

cream

Question 18

in chromotography,what does the rf value depend on

Answer 18

how soluble the solute is in the solvent

Question 19

in chromotography,why is the line substances are placed on drawn in pencil

Answer 19

since pencil wont dissolve in the solvent

Question 20

in chromotography,why does solvent height need to be lower than pencil line

Answer 20

so the substances dont dissolve into the solvent of the paper