2 - inorganic chemistry

Question 1

what is in group 1 on the periodic table?

Answer 1

alkali metals - lithium, sodium, potassium

Question 2

what is in group 7 on the periodic table?

Answer 2

halogens - chlorine, bromine, iodine

Question 3

test for hydrogen

Answer 3

squeaky pop test:
have hydrogen in test tube. If hydrogen is present in a test tube, a lighted splint held near its mouth will reignite with a squeaky pop.

Question 4

test for oxygen

Answer 4

take a glowing splint and place it in a sample of gas, if it re-ignites the gas is oxygen

Question 5

test for carbon dioxide

Answer 5

If carbon dioxide is bubbled through limewater, the limewater turns milky or cloudy white. if there’s no CO2, it will remain clear

Question 6

test for ammonia

Answer 6

dip damp, red litmus paper into ammonia solution. if ammonia is present, the paper will turn blue

Question 7

test for chlorine

Answer 7

use damp blue litmus paper. The blue colour will turn to red and then to white if chlorine is present.

Question 8

describe flame test

Answer 8

1. clean a platinum wire by dipping it in concentrated hydrochloric acid and then holding it in the Bunsen burner flame
2. moisten it again in the flame and dip into a small amount of the solid being tested.
3. put the wire under the flame again, and it should produce a colour.

Question 9

what colour does lithium (Li+) turn in the flame test?

Answer 9

red

Question 10

what colour does sodium (Na+) turn in the flame test?

Answer 10

yellow

Question 11

what colour does potassium (K+) turn in the flame test?

Answer 11

lilac

Question 12

what colour does calcium (Ca2+) turn in the flame test?

Answer 12

orange-red

Question 13

what colour does copper (Cu2+) turn in the flame test?

Answer 13

blue-green

Question 14

test for ammonium (NH4+) using sodium hydroxide

Answer 14

add sodium hydroxide solution and warm gently. If the compound contains ammonium ions, you will get ammonia gas produced which you can test with damp red litmus paper which it turns blue

Question 15

test for the presence of water using anhydrous copper(II) sulphate

Answer 15

When anhydrous copper(II) sulphate is mixed with water, it will absorb the water and change in appearance, becoming a blue crystalline solid

Question 16

physical test to show whether a sample of water is pure

Answer 16

by testing the freezing or boiling point. pure water will freeze at 0 degrees and boil at 100 degrees.