Tag: chemical reactions and equations

Questions Related to chemical reactions and equations

Which statements are correct in terms of chemical kinetic stuides?

chemistry chemical reactions and equations introduction to chemical kinetics understanding chemical kinetics rate of chemical reaction

  1. The quenching of a reaction can be made by cooling the reaction mixture.

  2. The quenching of a reaction can be made by diluting the reaction mixture.

  3. The reaction is supposed to be completed if it is kept for long time or strongly heated.

  4. None of the above

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Correct Option: A,B,C
Explanation:

The quenching of a reaction can be made by cooling as well as diluting the reaction mixture. The reaction is supposed to be completed if it is kept for a long time or strongly heated. Quenching a reaction is used to deactivate any unreacted reagents. It is also done by adding an antisolvent to induce precipitation, and collecting or removing the solids.

The rate constant for the reaction $2{N} _{2}{O} _{5}\rightarrow 4{N}{O} _{2}+{O} _{2}$, is $3.0\times 10^{-5}\sec^{-1}$. lf the rate is $2.40\times 10^{-5}$ mol litre $sec^{-1}$ then, the concentration of ${N} _{2}{O} _{5} ($in mol $litre^{-1})$ is:

chemistry chemical reactions and equations kinetic study of some first order reactions rate of chemical reaction endothermic and exothermic reactions

  1. 1.4

  2. 1.2

  3. 0.04

  4. 0.8

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Correct Option: D
Explanation:

Rate constant $= 3 \times 10^{-5} sec^{-1}$


So, from it's unit it is clear that, it is a first order reaction.


For first order reaction the expression will be:
Rate $= K [N _{2}O _{5}]$
$[N _{2}O _{5}] = \dfrac{2.40 \times 10^{-5}}{3 \times 10^{-5}}$$=\dfrac{2.40}{3} = 0.8$

For the reaction $2N _2O _5\, \rightarrow\, 4NO _2\, +\, O _2$, if $\displaystyle -\, \frac{d[N _2O _5]}{dt}\, =\, k _1[N _2O _5]$, $\displaystyle \frac{d[NO _2]}{dt}\, =\, k _2[N _2O _5]$, $\displaystyle \frac{d[O _2]}{dt}\, =\, k _3[N _2O _5]$.
What is the relation between $k _1, k _2$ and $k _3$?

chemistry chemical reactions and equations kinetic study of some first order reactions rate of chemical reaction endothermic and exothermic reactions

  1. $k _1\, =\, k _2\, =\, k _3$

  2. $2k _1\, =\, k _2\, =\, 4k _3$

  3. $2k _1\ =\, 4k _2\, =\, k _3$

  4. None of the above

Show answer
Correct Option: B
Explanation:

As we know, for a reaction: $2N _2O _5\, \rightarrow\, 4NO _2\, +\, O _2$

$\displaystyle -\, \frac{1}{2}\, \frac{d[N _2O _5]}{dt}\, =\, \frac{1}{4}\, \frac{d[NO _2]}{dt}\, =\, \frac{d[O _2]}{dt}$

So, $2k _1\, =\, k _2\, =\, 4k _3.$

Zinc corrodes in ____________________.

chemistry chemical reactions and equations effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. 2 $M$ alkaline solution

  2. 2 $M$ acid solution

  3. 2 $M$ neutral salt solution

  4. all of the above

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Correct Option: B
Explanation:

Corrosion requires acidic medium. Hence zinc corrodes in 2 $M$ acid solution.


Hence, option B is correct.