Sugar is separated from its impurities by
precipitation
crystallization
distillation
evaporation
Correct answer is B
No explanation has been provided for this answer.
Which of these properties gives a solid its definite shape?
strong intermolecular attraction
high melting point
high boiling point
weak intermolecular attraction
Correct answer is A
No explanation has been provided for this answer.
The shape of the hydrocarbon compound CH4 is
square planar
planar
linear
tetrahedral
Correct answer is D
No explanation has been provided for this answer.
How many moles of limestone will be required to produce 5.6g of CaO?
[Ca = 40, C = 12, O= 16]
0.20 mol
0.10 mol
1.12 mol
0.56 mol
Correct answer is B
CaCO3 → CaO + CO2
CaCO3 = 40 + 12 + 16 * 3 = 100, CaO = 40 + 16 = 56
56gt of CaO was produced by 100g of CaCO3
∴ 5.6g of CaO will produce by
(5.6 * 100)/56 = 10g of CaCO3
moles = mass/molar mass = 10/100 = 0.10m
Natural water collected from rivers and ponds contain oxygen, carbon (IV) oxide and
nitrogen
hydrogen
chlorine
sulphur
oxide
Correct answer is A
No explanation has been provided for this answer.