identifying gases and ions (51-53) (paper 1)

Question 1

what is the chemical test and result for hydrogen gas

Answer 1

• lit split
  = squeaky pop

Question 2

what is the chemical test and result for oxygen

Answer 2

• glowing splint
  = relights

Question 3

what is the chemical test and result for carbon dioxide

Answer 3

• add HCl
• bubble through limewater
  = goes cloudy white

Question 4

what is the chemical test and result for chlorine gas

Answer 4

• damp blue litmus paper
  = may turn red then bleached white

Question 5

what is the chemical test and result for ammonia gas

Answer 5

• add NaOH and warm gently
• damp red litmus paper
  = turns blue

Question 6

what is the chemical test and result for water

Answer 6

• white anhydrous copper sulfate
  = blue

Question 7

what is the physical test and result for water

Answer 7

• heat until boiling
  = will boil at 100

Question 8

how is a flame test carried out

Answer 8

• dip a nichrome wire into an acid (must be unreactive, colourless & high melting point)
• dip into the ionic solid
• put it in roaring bunsen flame

Question 9

why do we put the nichrome wire in a roaring bunsen flame

Answer 9

so the colour of the flame will not interfere

Question 10

what is the colour of the flame for lithium

Answer 10

red

Question 11

what is the colour of the flame for sodium

Answer 11

yellow

Question 12

what is the colour of the flame for potassium

Answer 12

lilac

Question 13

what is the colour of the flame for calcium

Answer 13

red-orange

Question 14

what is the colour of the flame for copper

Answer 14

blue-green

Question 15

when do you do a flmae test

Answer 15

for a metal ion

Question 16

what is the chemical test and result for sulphat

Answer 16

• add HCl
• add BaCl2
  = white precipitate

Question 17

what do you do when testing for a metal ion in a solution

Answer 17

add NaOH

Question 18

what do you do when identifying copper

Answer 18

add NaOH

Question 19

what do you do when identifying iron

Answer 19

add NaOH

Question 20

what is the colour of the precipitate fromed for copper

Answer 20

blue precipitate (Cu(OH)2)

Question 21

what is the colour of the precipitate formed for iron (II)

Answer 21

green precipitate (Fe(OH)2)

Question 22

what is the colour of the precipitate formed from iron (III)

Answer 22

brown precipitate (Fe(OH)3)

Question 23

how do you test for non-metall ions (chlorine, bromine, iodine)

Answer 23

• add HNO3 (aq)
• add AgNO3 (aq)

Question 24

what is the result for identifying chloride

Answer 24

white precipitate (AgCl)

Question 25

what is the result for identifying bromide

Answer 25

cream precipitate (AgBr)

Question 26

what is the result for identifying iodine

Answer 26

yellow precipitate (AgI)

Question 27

what are the instructions for writing an ionic equation for a precipitate

Answer 27

• write the formula of the precipitate on right side
• on left right the ions making it up
• balance
• state symbols