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.
54.0g
27.0g
13.5g
108.0gQ
Correct answer is A
Recall that
mass deposited = \(\frac{MmIt}{96500n}\)
Mm =108, t = 4830s
I = 10A, n = 1
m = 108 × 10 × (\(\frac{4830}{96500}\)) × 1
m = 54.0g
The shape of ammonia molecules is
trigonal planar
octahedral
square planar
tetrahedral
Correct answer is A
Ammonia = NH3
It has three bonds of hydrogen to the Nitrogen.
\(^{226}_{88}Ra\) → \(^x_{86}Rn\) + alpha particle
226
220
227
222
Correct answer is D
\(^{226}_{88}Ra\) → \(^x_{86}Rn\) + \(^4_{2}He\)
\(^4_{2}He\) = alpha particle
considering the summation of the mass number
226 = x + 4
x = 226 - 4
x = 222
When ΔH is negative, a reaction is said to be
endothermic
exothermic
reversible
ionic
Correct answer is B
When ΔH is negative, heat is liberated to the surrounding and it connotes an exothermic reaction.
ΔH = −ve
The ideal gas laws and equations are true for all gases at
low pressures and lower temperatures
low temperatures and high pressures
high pressures and high temperatures
low pressure and high temperatures
Correct answer is D
At high temperature and low pressure, the vanderwaal equation is reduced to ideal gas equation.
i.e, [P + \(\frac{a}{v^2}\)] [v - b] = RT is reduced to PV = nRT
Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure as the potential energy due to intermolecular forces, it becomes less significant compared with the particles kinetic energy and the size of the molecules, then it becomes less significant compared to the empty space between them.