First convert to moles:
0.5113 g / 17 g/mol = 0.0301 mol
Now create a ratio based on the reaction provided to solve for the unknown:
4 NH3 / -905.4 kJ = 0.0301 mol NH3 / x kJ
x = -6.808 kJ
The question is as follows: What is the% m / m of a solution in which 22 g of solute are dissolved in 44 g of solvent?
Answer: The% m/m of a solution in which 22 g of solute are dissolved in 44 g of solvent is 50%.
Explanation:
Given: Mass of solute = 22 g
Mass of solvent = 44 g
The percentage m/m is calculated using the following formula.

Substitute the values into above formula as follows.

Thus, we can conclude that the% m/m of a solution in which 22 g of solute are dissolved in 44 g of solvent is 50%.