The value of ΔGo for the precipitation reaction,
Ca2+(aq) + CO32-(aq) <=> CaCO3(s) is -48.1 kJ at 298 K.
Calculate the value of ΔG in kJ at 298 K if the concentrations of Ca2+(aq) and CO32-(aq) are 0.312 and 0.898, M respectively.

Respuesta :

Answer:

[tex]\Delta G=-44.9kJ[/tex]

Explanation:

We know, [tex]\Delta G=\Delta G^{0}+RTlnQ[/tex]

where Q is the reaction quotient and for this reaction, it is expressed as-

                        [tex]Q=\frac{1}{[Ca^{2+}][CO_{3}^{2-}]}[/tex]            

where species under third bracket represent concentrations in molarity.

T represents temperature in kelvin scale

Here T = 298 K

R = gas constant = 8.314 J/K

So, [tex]\Delta G=(-48.1\times 10^{3}J)+(8.314\frac{J}{K}\times 298K)ln(\frac{1}{0.312\times 0.898})[/tex]

or, [tex]\Delta G=-44948J[/tex]

or, [tex]\Delta G=-44.9kJ[/tex]

                           

The value of ΔG for the precipitation reaction is -44.948 kJ.

How we calculate the change in Gibb's free energy?

Chnage in Gibb's free energy of the reaction will be calculated as:

ΔG = ΔG° + RTlnQ, where

ΔG° = standard gibb's free energy = -48.1 kJ = -48100 kJ

R = universal gas constant = 8.314 J/k

T = temperature = 298 K

Q = ratio of the concentration of products to the reactants

Given chemical reaction is:

Ca²⁺(aq) + CO₃²⁻(aq) → CaCO₃(s)

Value of Q for the given reaction = 1 / [Ca²⁺][CO₃²⁻]

Given values of concentration of Ca²⁺ & CO₃²⁻ are 0.312 and 0.898 M respectively.

Now on putting all these values on the above equation, we get

ΔG = -48100 + (8.314 × 298) ln(1/  0.312 × 0.898)

ΔG = -44948 J

ΔG = -44.948 kJ

Hence, value of ΔG is -44.948 kJ.

To know more about gibb's free energy, visit the below link:

https://brainly.com/question/14415025