In an aluminum calorimeter, 25.00 g of I2 was burned in excess H2 to form HI. From the data below, establish the molar heat of reaction and write a thermochemical reaction.

Question

Data:
Mass I2 25.00 g
Mass Al 70.00 g
Specific heat Al 0.900 J/gC
Volume water 100.0 mL
Initial temperature 34.6C
Final temperature 23.8C

Answer 1

I2+...? 2HI
so for each mole of I2 burned, two moles of HI is achieved.

molesI2=25/127

Heatfrom I2 + HeatgainedbyAl + heatgainedwater=0
HeatfromI2+70(.900)(23.8-34.6) +200*4.19*(23.8-34.6)=0
solve for HeatfromI2
molareatofrecton for I2=heatfromI2 /2
that is the heat per mole of HI formed