Which of the following factors characterize members of the same homologous series?
The chemical property change gradually throughout the series
physical properties of members are similar
They have the same molecular formular
Successive members undergo changes in molecular formula by \(CH_{2}\)
Correct answer is D
The difference between every successive member of the same homologous series is always \(CH_{2}\) eg methane is \(CH_{4}\) and ethane is \(C_{2}H_{6}\), difference being \(CH_{2}\).
+2 to 0
+2 to -2
+2 to +4
+4 to +2
Correct answer is C
In NO, the oxidation number for nitrogen is N - 2 = 0
⇒ N = +2
In \(NO_{2}\), we have N - (2x2) =0
N - 4 =0
N =+4
Chemical reactions occurs when the colliding reactants have energy that is
less than the activation energy
greater than the activation energy
greater than the energy of the product
less than the energy of effective collision
Correct answer is B
The energy of the reactants must be more than the activation energy in order for product to be formed.
Soluble salts can be prepared by the following methods except
neutralization
reaction of an acid with trioxocarbonate(IV) salt
double decomposition
reaction of an acid with electropositive metals
Correct answer is C
Soluble salts cannot be produced by double decomposition( precipitation of an insoluble salt)
The property of a chemical reaction that is affected by the presence of a catalyst is
activation energy
free energy
equilibrium position
enthalpy change
Correct answer is A
The activation energy is the amount of energy that is required to form products in a reaction. The presence of a catalyst helps to speed up the reaction such that the energy needed for the reaction is reduced.