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 Sulphide which is insoluble in dilute hydrochloric acid is
FeS
CuS
ZnS
Na2S
Correct answer is B
Sulphides like PbS (lead (II) sulphide) and CuS (copper (II) sulphide) are insoluble in acidified solutions.
A substance that is used as a ripening agent for fruits is
ethene
propane
methane
butane
Correct answer is A
No explanation has been provided for this answer.
According to Charles' law, the volume of a gas becomes zero at
0°C
-100°C
-273°C
-373°C
Correct answer is C
No explanation has been provided for this answer.
0.89 mol
1.90 mol
3.80 mol
5.70 mol
Correct answer is A
No explanation has been provided for this answer.
negative
zero
positive
indeterminate
Correct answer is A
\(\begin{array}{c|c}
\text{Enthalpy Change [ΔH]} & \text{Entropy Change [ΔS]} & \text{Gibbs free Energy[ΔG]} \\
\hline
\text{Positive} & \text{Positive} & \text{depends on T, may be + or -} \\ \hline \text{Negative} & \text{Positive} & \text{always negative} \\ \hline \text{Negative} & \text{Negative} & \text{depends on T, may be + or -} \\ \hline \text{Positive} & \text{Negative} & \text{always positive} \end{array}\)
ΔG= ΔH − TΔS.
To determine whether ΔG will be positive or negative, the value of ΔH(change in enthalpy) and ΔS (change in entropy) must be given. Likewise the temperature.