The general formula of an alkyl halide (which represent the halide) is?
CnH2n - 2X
CnH2n + 1X
CnH2n + 2X
CnH2nX
CnH2n - 1
Correct answer is B
No explanation has been provided for this answer.
An efflorescent compound is a substance that?
absorbs water froom the air without dissolving in it
is capable of giving off coloured luminosity
gives out water to the atmosphere
absorbs water from the air and dissolves in it
gives out its water of crystallization on heating
Correct answer is C
Efflorescence is a phenomenon where a crystalline salt loses all or part of its water of crystallization when exposed to the atmosphere to form a lower dehydrate or an anhydrous salt.
The scale formation in a kinetic used for boiling water is caused by the presence in water of?
calcium sulphate
calcium carbonate
calcium hydrogen carbonate
calcium hydroxide
magnesium sulphate
Correct answer is C
The scale is produced when soluble Ca(HCO3)2 breaks down on heating to form insoluble CaCO3
eqn Ca (HCO3)2(aq) -----> CaCO3 (s) + CO2 (g) + H2O (l)
What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?
All the nitrate will decompose to their respective metals
The nitrates of calcium and potassium will decomposes to their nitrites
Only copper nitrate decomposes to the metal
Only the nitrates of zinc and copper will decompose to their oxides
The nitrates of calcium, zinc and copper decompose to their oxides
Correct answer is E
The nitrates of calcium, zinc and copper decompose to their metal oxides
There were more aluminium atoms in Q than P
The heat given off in retarded the reaction
Q generated more pressure than P during the reaction
P generated more pressure than Q
Q has a greater surface area for the reaction than P
Correct answer is E
No explanation has been provided for this answer.