Question

4. Give an example of a reaction where the following are
involved
(a) Evolution of heat (b) Absorption of heat
(c) High pressure is required​

Answer 1

Answer:

following are the example of:-

a) evolution of heat :- All reactions which are Exothermic are accompanied by evolution of heat. One such example is burning of methane. Reaction is as Follows:

CH4(g) + 2O2 (g) → CO2 (g)+ 2H2O (g)

b) Absorption of heat :- Example

There are numerous endothermic reactions. One example, which can be carried out in a lab, is the reaction between barium hydroxide octahydrate and ammonium nitrate. This reaction can be demonstrated by combining, in a 2:1 ratio, solid barium hydroxide octahydrate with dry ammonium nitrate in a small beaker at room temperature. As the reactants are mixed and new products are formed, the temperature of the beaker will drop dramatically by roughly 80 degrees Fahrenheit to a frigid subzero level. As the reaction absorbs heat, the temperature of the immediate surroundings drop significantly, as evidenced by the temperature of the beaker.

c) High pressure required:-

N2 + 3H2 -----> 2NH3

pressure = 200 atm

Explanation:

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Answer 2

Answer:

Explanation:

(A)The system absorbs this extra energy as heat from the surroundings. Expressing exothermic and endothermic changes in numbers. Here is an exothermic reaction, showing the amount of heat evolved: This shows that 394 kJ of heat energy are evolved when equation quantities of carbon and oxygen combine to give carbon dioxide ...

(B)The thermal conductivity is better, but the heat absorbing power is still poor. Water can only absorb a limited amount of heat before it boils. The real cooling comes from a phase change, such as a liquid to gas transition as in the evaporation of liquid nitrogen.

(C)Changing the pressure on a reaction which involves only solids or liquids has no effect on the rate. Example 1: In the manufacture of ammonia by the Haber Process, the rate of reaction between the hydrogen and the nitrogen is increased by the use of very high pressures