Chemical Element

Question 1

uses of sulphur

Answer 1

*manufacture H2SO4 through the contact process. *used to manufacture gunpowder, matches, and vulcanizer

Question 2

what state of matter is chlorine at room temperature

Answer 2

gaseous

Question 3

what state of matter is bromine at room temperature

Answer 3

liquid

Question 4

what state of matter is iodine at room temperature

Answer 4

solid

Question 5

describe the preparation of chlorine

Answer 5

Oxidation of HCL with either KMNO4 or MnO2

Question 6

describe chlorine gas

Answer 6

A greenish yellow gas which is poisonous

Question 7

describe bromine liquid

Answer 7

a dark red liquid with unpleasant poisonous vapour

Question 8

describe solid iodine

Answer 8

a dark shiny solid which can produce vapour on heating

Question 9

describe the solubility of the halides

Answer 9

chlorine and bromine are moderately soluble in H2O whilst iodine is sparingly soluble…however they are all well soluble in organic solvents

Question 10

describe Br and I reactions with hydrocarbons

Answer 10

Br reacts with hydrocarbons whilst I shows little reaction with hydrocarbons

Question 11

uses of Chlorine

Answer 11

*Used in manufacture of tetrachloromethane *used to manufacture polyvinyl chloride(pvc)-a form of plastic *used to manufacture comping like DDT. *very good bleaching agent *used a safe disenfrctant in treating water

Question 12

uses of bromine

Answer 12

*used to manufacture 1,2-dibromoethane *used to produce silver bromide which is useful in photographic films

Question 13

uses of iodine

Answer 13

used to manufacture of silver iodide which b is b useful in photographic films *also used in making iodoform(CHI3) *also used in colour photography

Question 14

what are the three isotopes of hydrogen

Answer 14

Proton , deutrium, and tritium

Question 15

how is hydrogen gas prepared

Answer 15

*REACTING Na metal with cold water (2Na +2H2O》2 NaOH +H2. *reaction of carbon with water…i.e C+H2O 》CO + H2 and also CO+H2O》CO2+H2. * also reaction of NaH with H2O (NaH+H2O》NaOH+H2)

Question 16

what are the allotropes of hydrogen

Answer 16

Parahydrogen (speed directed towers opposite paths) *and Orthohydrogen (speed directed towards equal paths.

Question 17

uses of hydrogen

Answer 17

*to fill baloons. *in welding using oxyhydrogen flame. *production of margarine through hydrogenation.

Question 18

in which forms does Phosphorus exist??

Answer 18

Apatite and Rockphosphate

Question 19

how is phosphorus prepared

Answer 19

by heating rockphosphate

Question 20

what are the allotropes of phosphorus

Answer 20

Red phosphate. white phosphate and black phosphate

Question 21

similarities of N and P.

Answer 21

have the same group but different periods *both gain three electrons in their ionic bond. *usually form covalent compounds

Question 22

how is nitrogen prepared

Answer 22

*by heating ammonium nitrate to produce nitrogen gas. *reacting NH3 with CuO. (2NH3+3CuO》N2+3H2O+3Cu

Question 23

what percentage of Oxygen occurs in the air on an average..and why

Answer 23

21% …due to the cycle of photosynthesis

Question 24

how is oxygen prepared

Answer 24

by reducing Ag2O or Pb2O, also chromium