MCQ 11 Mark
The order of radioactive disintegration reaction is -
- A0
- ✓1
- C2
- D3
Answer
View full question & answer→Correct option: B.
1
B
36 questions · timed · auto-graded
Explanation:
Collision diameter will be least for the low molecular weight.
$\text{d}\alpha\frac{1}{\text{M}}$
In this case, Co2 has the highest molecular weight.
Explanation:
The minimum energy required to start a reaction is called activation energy.
Explanation:
Activation energy of a chemical reaction is related to rate constant of a reaction at two different temperatures i.e., K1 and K2 respectively.
Solution:
$\log\frac{\text{k}_2}{\text{k}_1}=\frac{\text{E}_\text{a}}{2.303}\Big(\frac{1}{\text{T}_1}-\frac{1}{\text{T}_2}\Big)$
Where, Ea = activation energy.
T2 = higher temprature
T1 = lower temprature
K1 = rate constant at temprature T1
K2 = rate constant at temprature T2
The equation is known as Arrehenius equation.
Explanation:
It is impossible to perform 100% of the reaction, whole of the substance never react.
Explanation:
Activation energy may be greater than heat of reaction or lesser than threshold energy.
At room temperature, most of the molecules have less than the threshold value.
Hence, if energy is supplied to the reactant molecules in the form of light or heat, they absorb that energy and reach a higher energy level which is equal to or greater than the threshold energy level, is called as activation energy.
Activation energy (Ea) = Threshold energy - Average kinetic energy of molecules
Explanation:
For a zero order reaction,
Rate = K[A]0
So, rate of reaction depends on K only. K is called rate constant or decay constant.
Explanation:
Reaction kinetics is the study of reaction rates, mechanisms, and the factors that influence reaction rates.
Explanation:
The value of rate constant of a pseudo first order reaction depends on the concentration of reactants present in excess.
Explanation:
Catalyst can change the activation energy of the reaction by changing the path of the reaction.
Explanation:
$\text{t}_{\frac{1}{2}}=\frac{0.693}{\text{k}}=\frac{0.693}{0.6932\text{hr}^{-1}}=1\text{hr}$
Explanation:
If there is substantially lower rate of reaction than the collision frequency then the activated complex formed will be long-lived and the reaction will proceed at a slower rate.
Because of low energy, the activated complex exists for an extremely long period of time and activated complex will neither reforms to form products.
Explanation:
Activation energy = It is defined as the least possible amount of energy (minimum) which is required to start a reaction or the amount of energy available in a chemical system for a reaction to take place.
The activation energy for the water formation reaction is very high at room temperature due to this reaction does not take place,
Explanation:
The rate of a reaction can be defined as the change in concentration of a reactant of product in unit time. To be more specific, it can be expressed in term of:
$\text{r}=\frac{-\text{dx}}{\text{dt}}$ (r = rate)
Explanation:
The integrated rate law for the first order reaction is [A] = [A]0e−kt.
Substituting the value of [A] = a − x and [A]0 = a in the above expression.
We get, a − x = ae−kt.
Rearrange above expression, x = a(1 − e−kt).
Explanation:
A catalyst does not alter Gibbs energy, (G) of a reaction. It catalyses the spontaneous reactions but does not catalyse non-spontaneous reactions.
Explanation:
These are the characteristics of effective collisions.
Effective collisions are collision between two reactants with the appropriate orientation & with sufficient energy to overcome the activation energy barrier.
The number of effective collisions increases exponentially with an increase in temperature.
Explanation:
$\text{k}=\text{Ae}^{\frac{-\text{E}_\text{a}}{\text{RT}}}$
$\therefore$ k depends on temperature.
Explanation:
r = [A][B]0
OR = 1 + o = 1
Explanation:
Activation energy is the energy needed by reactant molecules to gain threshold energy level.
Explanation:
Activation Energy:- The minimum energy which must be available to a chemical system with potential reactants to result in a chemical reaction
Activation energy may also be defined as the minimum energy required to start a chemical reaction.
The activation energy of a reaction is usually denoted by Ea and given in units of kilojoules per mole (kJ/ mol) or kilocalories per mole (kcal/ mol).
Explanation:
because molecularity can never be zero.
So, for zero-order reaction, molecularity and order can never be same.
Explanation:
For any unimolecular reaction, only one reactant is involved in rate determining step and the order and molecularity of rate determining or slowest step are one.
$\text{A}\xrightarrow{\ \ \ \ \ }\text{B}$
Rate = k[A].
Order is same as molecularity.
Explanation:
For a single step reaction, the order and molecularity will be the same.
Explanation:
→ As the pressure increases collision frequency increases.
→ Vice versa pressure is decreased to half, frequency of collision decreases to half.
Energy is always released.
Reactants may be formed.
Explanation:
Activated complex is formed at the highest level of energy of the system. It is unstable and decomposes to give products with release of energy. Reactants may be formed if the reaction is reversible.