A 92.2 mL sample of 1.00 M NaOH is mixed with 46.1 mL of 1.00 M H2SO4 in a large

Question

A 92.2 mL sample of 1.00 M NaOH is mixed with 46.1 mL of 1.00 M H2SO4 in a large Styrofoam coffee cup; the cup is fitted with a lid through which passes a calibrated thermometer. The temperature of each solution before mixing is 22.85 °C. After adding the NaOH solution to the coffee cup and stirring the mixed solutions with the thermometer, the maximum temperature measured is 30.50 °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.

Part 1 (1.3 pts) lid 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.

Explanation / Answer

2NaOH + H2SO4 --------------> Na2SO4 + 2H2O
no of moles of NaOH = molarity * volume in L
                     = 1*0.0922 = 0.0922 moles
no of moles of H2So4 = molarity * volume in L
                      = 1*0.0461   = 0.0461 moles
part-2
from balanced equation NaOH : H2So4
                        2   : 1
                     0.0922 : 0.0461
                     
No left of NaOH or H2So4

Total volume of solution = 92.2+46.1   = 138.3ml
mass of solution          = volume * density
                          = 138.3 *1 = 138.3g
q = mCDT
    = 138.3*4.18*(30.5-22.85)
    = 4422.42J   = 4.42242KJ
heat energy converted to KJ to Kj/mole

DH = -4.42242/0.0461 = -95.93KJ/mole

heat per mole of H2So4 = -95.93KJ/mole

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