A. 40.0 ml of 1.0 M NaOH solution whose initial temperature is 25.4 C is mixed w

Question

A. 40.0 ml of 1.0 M NaOH solution whose initial temperature is 25.4 C is mixed with 60.0 ml of 1.0 M HCL solution in a calorimeter. The final temperature of the mixture was found to be 30.8C. If the heat capacity of the calorimeter is 21.0J/C and if the density of the salt solution is 1.00 g/ml, what is the enthalpy change in kilojoules per mole for this reaction.?The specific heat of the salt solution is 4.01J/gC. B. 40.0 grams of water at 64.2C is added to 60.0 grams of water at 25.0C in a calorimeter. The final temperature of this solution was found to be 39.6C. What is the heat capacity of the calorimeter? Please show work.

Explanation / Answer

moles of NaOH = 40 x 1 / 1000 = 0.04

moles of HCl = 60 x 1 / 1000 = 0.06

total mass of solution = 60 + 40 = 100 g

temperature difference = 30.8 - 25.4 = 5.4 oC

Q = m Cp dT + Cp dT

    = 100 x 4.01 x 5.4 + 21 x 5.4

    = 2278.8 J

here limiting reagent is NaOH. so

delta H = - Q / n = - 2278.8 x 10^-3 / 0.04

            = 56.97 kJ/mol

enthalpy change = - 56.97 kJ/mol

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.