Enthalpy of the reaction

Question

What is the standard enthalpy of the reaction, in kJ, at 298K for:

2 A (aq) + 1 B (aq) <--> 2 C (aq) + 1 D (aq)

if  ΔH° (A)= 40.9723 kJ/mol , ΔH° (B) = -3.6396 kJ/mol, ΔH° (C) = 45.0956 kJ/mol, and ΔH° (D) = 83.8128 kJ/mol

Answer 1

The key idea of this problem is to understand how to use the information given in the standard of enthalpy formula to calculate the enthalpy of the reaction given.

Given the standard of enthalpy reaction, you will need to plug in the numbers given to you in the problem.

Key Takeaways:

1) Make sure to account for the number of moles of each product and reactant given in the equation.

2) Multiply the enthalpy for each substance respectively with the number of moles for that substance

3) ***NOTE: that to calculate standard enthalpy it's the sum of enthalpy (products) - sum of enthalpy (reactants)