Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The velocity, V of a gas is related to its mass, M by (k = proportionality constant)
V = kM
V = kM12
V = kM2
V = (kM)12
Correct answer is B
Recall:
V = √3RTM
∴
V = \frac{k}{\sqrt{M}}
V = \frac{k}{M^{\frac{1}{2}}}
HCOOH
NaHCO_3
FeCO_3
H_2C_2O_4
Correct answer is D
It should be noted that for X to liberate CO_2, X must be a carbonate or an oxalate. Since X decolorizes KMnO_4, X must be an oxalate.
Therefore, X is H_2C_2O_4.
Which of the following conditions will most enhance the spontaneity of a reaction?
\DeltaH is negative and greater than T\DeltaS
\DeltaH is negative and \DeltaS = 0
\DeltaH is positive and less than T\DeltaS
\DeltaH is positive and equal to T\DeltaS
Correct answer is A
No explanation has been provided for this answer.
10g
25g
20g
15g
Correct answer is A
Equation: Ca(HCO_3)_2 \to CaCO_3 (precipitate) + H_2O + CO_2 (in the presence of heat)
V = 200 cm^3 = 0.2 dm^3
C = 0.5 mol/dm^3 = 0.5M
N = CV \implies N = 0.5 \times 0.2
= 0.1 mole
From the equation 1 mole of Ca(HCO_3)_2 gives 100g of CaCO_3
(1 mole CaCO_3 = 40 + 12 + (3 x 16) = 100g\)
0.1 mole of Ca(HCO_3)_2 gives x g of CaCO_3.
\frac{1}{0.10} = \frac{100}{x}
x = 100 \times 0.10 = 10 g
addition of water, filtration, evaporation to dryness and sublimation
filtration, evaporation to dryness, addition of water and sublimation
sublimation, filtration, evaporation and addition of water
sublimation, addition of water, filtration and evaporation to dryness
Correct answer is A
Process:
Add water to the mixture and then filter. The resultant is a salt solution as your filtrate and a mixture of iodine and sand as your residue. Evaporate the filtrate to dryness to get your sodium chloride (salt). Heat the residue to sublime the iodine from the sand.
Addition of water \to Filtration \to Evaporation \to Sublimation.