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.
A molar solution of caustic soda is prepared by dissolving
40 g NaOH in 100 g of water
40 g NaOH in 1000 g of water
20 g NaOH in 500 of solution
20 g NaOH in 1000 g of solution
20 g NaOH in 80 g of solution
Correct answer is B
A molar solution implies concentration in terms of moles/liter. The respective atomic weights for NaOH are: Na - 23,0 - 16 and H - 1, so the molecular weight, is 23 + 16 + I = 40. Thus 40 grams of NaOH equals one mole of NaOH, and a 1 molar solution of NaOH will contain 40 grams of NaOH chemical in 1000grams of water.
2.24 dm 3
2.24 cm3
1. 123
1. 12dm 3
4. 48 dm 3
Correct answer is D
\(NH_{4}NO_{2}\) \(\to\) \(N_{2}\) + \(2H_{2}O\)
\(64g\) \(\to\) \(22.4dm^{3}\)
\(3.2g\) will give \(\frac{22.4}{64}\) \(\times\) \(\frac{3.2}{64}\)
= \(1.12dm^{3}\)
40 cm 3
20 cm 3
30 cm 3
10cm 3
5cm 3
Correct answer is D
2H2 + O2 ------2H2O
2V 1V 2V
20cm3 20cm3 -------
20cm3 10cm3 20cm3
Residual gas = 20cm3 - 10cm3 of 02 = 103
Sodium chloride may be obtained from brine by
titration
decantation
distillation
evaporation
sublimation
Correct answer is D
No explanation has been provided for this answer.
X and Z
Y
X
Z
Correct answer is C
Aromatic compounds burn with a yellow sooty flame and they don't decolorise bromine water, since bromine is not electrophilic enough except in the presence of a strong Lewis catalyst.