14
12
11
10
Correct answer is A
K\(_{2}\)Cr\(_{2}\)O\(_{7}\) + HCl → Cl\(_{2}\) + KCl + CrCl\(_{3}\) + H\(_{2}\)O
Balancing the equation, we have
K\(_{2}\)Cr\(_{2}\)O\(_{7}\) + 14HCl → 3Cl\(_{2}\) + 2KCl + 2CrCl\(_{3}\) + 7H\(_{2}\)O
Carbon (II) oxide
Carbon (IV) oxide
Oxygen
Nitrogen
Correct answer is C
2CO + O2 → 2CO2
50cm3 → 25cm3
20% * 150 = 30cm3
30 cm3 is the volume of oxygen available for the reactions. But only 25 cm3 is required; therefore O2 is in excess
Which of the following compounds is composed of Al, Si, O and H?
Epsom salt
Limestone
Clay
Urea
Correct answer is C
Clay is Alumina silicate and the formula is AL2O3 2SiO2 2H2O
Sieving is a technique used to separate mixture containing solid particles of
small sizes
large sizes
differents sizes
the same sizes
Correct answer is C
No explanation has been provided for this answer.
A mixture of iodine and sulphur crystals can be separated by treatment with?
Water to filter off sulphur
carbon (IV) sulphide to filter off iodine
ethanoic acid to filter off sulphur
methanol to filter off iodine
Correct answer is B
A mixture of iodine and sulphur can be separated by adding Carbon disulphide that is (CS₂) then stir the solution and filter it . As sulphur dissolved in CS₂, so it come into filter and got separated from the mixture.