As an approximation, we can assume that proteins exist either in their native (physiologically relevant) state or in a denatured state. The standard molar enthalpy and entropy of denaturationof a certain protein are 512 kJ/mol and 1.60 kJ/(mol K), respectively. Assume that DHand DSare independent of temperature. a. Commenton the signs thinking about protein denaturation. b. Calculate the standard molar free energy of denaturation. c. Calculate the temperature at which the denaturation becomes spontaneous.

Explanation:

a) The standard molar enthalpy of denaturation of protein = ΔH = 512 kJ/mol

The standard molar entropy of denaturation of protein = ΔS = 1.60 kJ/mol K

The Gibbs free energy is given by ;

ΔG = ΔH - TΔS

Here in the question value ΔH and ΔS are positive and independent of temperature.

This means that value of Gibbs free energy depends only upon temperature that is at lower denaturation of protein will be non spontaneous and at high temperatures denaturation of protein will spontaneous.

b) The standard molar free energy of denaturation of protein at 25°C.

T = 25°C = 25+273 K = 298 K

ΔG = ΔH - TΔS

  = 512 kJ/mol - 298 K × (1.60 kJ/mol K) =  35.2 kJ/mol

c) If the value ,ΔG < 0, then reaction is spontaneous.

Putting , ΔG =  0

ΔG = ΔH - TΔS

0 =512 kJ/mol - T × (1.60 kJ/mol)

512 kJ/mol =T × (1.60 kJ/mol K)

So, this means that above 320 Kelvins the denaturation of protein will be spontaneous.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !