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.
-122kJ
-132kJ
-88kJ
-60kJ
Correct answer is B
No explanation has been provided for this answer.
yellow to green
orange to green
yellow to red
orange to red
Correct answer is B
Potassium dichromate is an oxidising agent in organic chemistry. It is used to oxidize alcohols.
In an aqueous solution the color change exhibited can be used to test for distinguishing aldehydes from ketones. Aldehydes reduce dichromate from the +6 to the +3 oxidation state, changing color from orange to green. This color change arises because the aldehyde can be oxidized to the corresponding carboxylic acid.
Which of the following reactions is an oxidation process?
2H\(^+\) + 2e\(^-\) \(\to\) H\(_2\)
2O\(^{2-}\) + 4e\(^-\) \(\to\) O\(_2\)
OCl\(^-\) + H\(_2\)O + 2e\(^-\) \(\to\) 2OH\(^-\) + Cl\(^-\)
Cl + e\(^-\) \(\to\) Cl\(^-\)
Correct answer is B
No explanation has been provided for this answer.
k[P]\(^x\)[Q]\(^y\)
\(\frac{m[R][S]}{x[P]y[Q]}\)
\(\frac{[P]^x[Q]^y}{[R]^m[S]^n}\)
\(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\)
Correct answer is D
Given:
xP + yQ ⇌ mR + nS
Let us assume they are all in aqueous solution
k = \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\)
the equilibrium will shift
rate of forward reaction will increase
rate of backward reaction will increase
rates of forward and backward reaction are not affected
Correct answer is C
Given: The equation below
A\(_{(s)}\) + 2B\(_{(g)}\) → 2C\(_{(aq)}\) + D\(_{(g)}\)
According to Le Chatelier's Principle:
Pressure changes affects only the gaseous reactants and products
There must be different amount of gaseous particles on both sides.
Generally; a decrease in the pressure shifts the equilibrium position in favor of the side with larger volume of gases.
I.e rates of backward reaction.