Heat released when diluting a concentrated sodium hydroxide solution
Thread Content
How is the heat released when a concentrated sodium hydroxide solution is diluted? For example, how much heat is generated when 1 kilogram of 34% concentrated sodium hydroxide solution is diluted to a 5% solution?
The enthalpy values of sodium hydroxide solutions at different concentrations can be determined; by applying the law of conservation of mass for sodium hydroxide, the difference in enthalpy values between the two solutions can be calculated!
The heat of solution for sodium hydroxide in water is 10.18 kcal/mol. In 1 kg of a 34% NaOH aqueous solution, there are 8.5 mol of sodium hydroxide, so the heat of solution is 86.53 kcal
It’s very convenient to look up data on heat of solution.
The heat of solution of sodium hydroxide in water was found to be 10.18 kcal/mol. Then, multiply the heat of solution by the number of moles of sodium hydroxide to get the result!
Not much. 10.18 is the heat of solution when solid sodium hydroxide is dissolved in an infinitely dilute solution, and it cannot be used to calculate the situation at this point. The heat of dilution at different concentrations should be determined first, and then calculations can be carried out; I haven’t looked up the specific values either.