Question

5. Why rate of reaction is fastest, if distilled water is not added to 50 mL (i.e D flask) 0.1 M
Na,s,o, ?
Ans.​

Answer 1

Answer:R

ATE of reaction can be measured either in terms of decrease in concentration

of any one of the reactants or increase in concentration of any one of the

products with time. For a hypothetical reaction,

A → B

[A] Rate of reaction

T

∆

= −

∆

∆[B]

=

∆T

Factors such as concentration, temperature and catalyst affect the rate of a

reaction. In this unit you will learn the technique of determining the rate of a

reaction and technique of studying the effect of concentration and temperature

on the reaction rate.

Explanation:lows:

Na2

S2O3

(aq) + 2HCl (aq) → 2NaCl (aq) + H2O(l) + SO2

(g) + S(s)

Ionic form of the above reaction is written as:

2–

2 3 S O (aq) + 2H+ (aq) → H2O (l) + SO2

(g) + S(s)

The property of the colloidal solution of sulphur to make the system

translucent is used to study the rate of precipitation of sulphur. The rate of

precipitation of sulphur increases with an increase in the concentration of the

reacting species or with an increase in the temperature of the system. With an

increase in the concentration, the number of molecular collisions per unit time

between the reacting species increase and consequently chances of product

formation increase. This results in an increase in the rate of precipitation of

sulphur. Similarly, on increasing the temperature, the kinetic energy of the

reacting species increases, so the number of collisions that result in the formation

of products increase leading to a faster rate of reaction.