10 Question (3 points) See page 223 A 102.2 mL sample of 1.00 M NaOH is mixed wi

Question

10 Question (3 points) See page 223 A 102.2 mL sample of 1.00 M NaOH is mixed with 51.1 mL of 1.00 MH2SO4 n a large Styrofoam coffee cup; the cup is fitted with alid through which passes a calibrated thermometer. The temperature of each solution before mixing is 22.05°C. After adding the NaOH solution to the coffee cup and stirring the mixed solutions with the thermometer, the maximum temperature measured is 31.70 °C. Assume that the density of the mixed solutions is 1.00 g/mL, that the specific heat of the mixed solutions is 4.18 J/(g. C), and that no heat is lost to the surroundings. 1st attempt Part 1 (1point) See Periodic Table Write a balanced chemical equation for the reaction that takes place in the Styrofoam cup. Remember to include phases in the balanced chemical equation. Part 2 (1point) Is any NaOH or H2SO4 left in the Styrofoam cup when the reaction is over? Choose one: A. No B. Yes Part 3 (1 point) Q See Hint Calculate the enthalpy change per mole of H2SO4 in the reaction. kJ/mol

Explanation / Answer

Part 1)

H2SO4 (aq) +   2 NaOH (aq)   ----------------> Na2SO4 (aq) + 2 H2O (l)

part 2)

moles of NaOH = 102.2 x 1 / 1000 = 0.1022

moles of H2SO4 = 51.1 x 1 / 1000 = 0.0511

H2SO4 (aq) +   2 NaOH (aq)   ----------------> Na2SO4 (aq) + 2 H2O (l)

    1                          2

0.0511               0.1022

answer : NO

No NaOH or H2SO4 left when reaction over.

part 3)

mass of solution = 102.2 + 51.1 = 153.3 g

temperature difference = 31.70 - 22.05 = 9.65 oC

Q = m Cp dT

    = 153.3 x 4.18 x 9.65

    = 6189.6 J

delta H = - Q /n

            = - 6189.6 x 10^-3 / 0.0511

delta H = - 121 kJ/mol

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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