1. The standard heat of formation of glucose and lactic acid are -1274.45 and -694.04 kJ/mole, respectively. The molar heat capacity of the two compounds are 218.86 and 127.6 J/(mol)K

a.) What is the total heat of reaction at 25 degree Celsius for the formation of lactic acid from glucose?
b.) What value would be estimated for the heat of the reaction proceeded at the physiological temperature of 37 degree Celsius?

How many moles of lactic acid will yield from one mole of glucose. Multply that number by the Hf lactic acid, and subtract one glucose Hf.

How about the change in the temperature? Would it cause the answers to somehow change? Isn't it that Hf depends on the temperature also?

Yes, you have to correct that according to the correction model in your text. There are several correction models, I do not know which one you have been exposed to.

To answer the first part of your question, you can calculate the total heat of reaction for the formation of lactic acid from glucose by subtracting the standard heat of formation of glucose from the standard heat of formation of lactic acid.

Total heat of reaction = Hf(lactic acid) - Hf(glucose)

Using the given values:
Total heat of reaction = (-694.04 kJ/mole) - (-1274.45 kJ/mole)
= -694.04 kJ/mole + 1274.45 kJ/mole
= 580.41 kJ/mole

So the total heat of reaction at 25 degrees Celsius for the formation of lactic acid from glucose is 580.41 kJ/mole.

To answer the second part of your question, if the reaction is proceeding at a different temperature, you can use the molar heat capacity values to calculate the change in heat with respect to temperature (ΔHt).

ΔHt = (Cp * ΔT) / 1000

Where ΔT is the change in temperature in Kelvin, Cp is the molar heat capacity, and 1000 is used to convert units from J to kJ.

Using the given values for glucose molar heat capacity (218.86 J/(mol)K) and lactic acid molar heat capacity (127.6 J/(mol)K) and assuming the change in temperature is from 25 degrees Celsius to 37 degrees Celsius (which is a change of 12 Kelvin):

For glucose:
ΔHt(glucose) = (218.86 J/(mol)K * 12 K) / 1000
= 2.63 kJ/mol

For lactic acid:
ΔHt(lactic acid) = (127.6 J/(mol)K * 12 K) / 1000
= 1.53 kJ/mol

To estimate the heat of the reaction at the physiological temperature of 37 degrees Celsius, you need to add the change in heat due to temperature to the total heat of reaction:

Estimated heat of reaction at 37 degrees Celsius = Total heat of reaction + ΔHt

Using the previously calculated total heat of reaction (580.41 kJ/mole):

Estimated heat of reaction at 37 degrees Celsius = 580.41 kJ/mol + 2.63 kJ/mol + 1.53 kJ/mol
= 584.57 kJ/mol

So the estimated heat of the reaction at 37 degrees Celsius is 584.57 kJ/mol.