Chemistry, asked by vinojsingh27, 10 months ago

Caculate the heat of hydration of Copper sulphate to form hydated copper sulphate GIVEN that the heat of Solution Of hydrate Copper Sulphate are -66.5KJ + 11.0 KJ​

Answers

Answered by hinakamran2182
3

Answer:

Hess’s law states that total enthalpy change for a reaction is

independent of the route by which the chemical change takes place

Hess’s law is a version of the first law

of thermodynamics, which is that

energy is always conserved.

2H (g) + 2Cl(g)

H2 + Cl2

2HCl (g)

a

b

ΔH

On an energy level diagram the directions of the arrows can

show the different routes a reaction can proceed by

In this example one route is arrow ‘a’

The second route is shown by arrows ΔH plus arrow ‘b’

So by applying Hess’s law

a = ΔH + b

And rearranged

ΔH = a - b

H+

(g) + Br -

(g) H+

(aq) + Br -

(aq)

H (g) + Br (g) HBr (g)

a

c

d

ΔH

Interconnecting reactions can also be shown diagrammatically.

In this example one route is arrow ‘a’ plus ΔH

The second route is shown by arrows ‘c’ plus arrow ‘d’

So a+ ΔH = c + d

And rearranged

ΔH = c + d - a

The two routes must have the same starting point and the

same end point

Energy

CuSO4

(aq)

CuSO4 (s) + 5H2O (l) CuSO4

.5H2O (s)

+ 11kJmol-1 = -66.1 kJmol-1

∆H reaction

+ aq + aq

∆H reaction

+11kJmol-1 -66.1 kJmol-1

∆H reaction = -66.1 - 11

= -77.1 kJmol-1

This Hess’s law is used to work out the

enthalpy change to form a hydrated salt

from an anhydrous salt.

This cannot be done experimentally

because it is impossible to add the exact

amount of water to hydrate the copper

salt and it is not easy to measure the

temperature change of a solid turning into

another solid.

Often Hess’s law cycles are used to measure the enthalpy change for a reaction that cannot be measured

directly by experiments. Instead alternative reactions are carried out that can be measured experimentally.

Explanation:

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