Which of the following statements about catalyst is false?
biological catalysts are called enzymes
catalyst do not appear in the balanced equation
catalyst reduce the activation energy for a reaction
catalysts do not alter the mechanism of the reaction and never appear in the rate low
Correct answer is D
No explanation has been provided for this answer.
-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 = \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\)