Aim: to determine the change in enthalpy for the hydration of magnesium sulfate using Hess’ Law.

Hypothesis: It looks like there are being more bonds formed than broken in this reaction, therefore, I think the change in enthalpy will be exothermic.

- Temperature of the surroundings (this should not effect our experiment because it will be carried out in a polystyrene cup).

- Air pressure (will have no effect on our experiment as it should not change during the short time our experiment will take.)

- Temperature of the water (there will be an error with the thermometer)

- Mass of MgSO4 and MgSO4•7H2O (error on the electronic balance)

- Specific Heat Capacity (we are using the specific heat capacity of water)

- Volume of Water – this is the controlled variable, as we will use the same amount of water in each experiment.

= 1641.46J/15.498g n = m ÷ Mr

The theoretical answer for the endothermic reaction (MgSO4 + H2O à Mg2+ + SO42- + H2O) is –84kJmol-1, and the theoretical answer for the exothermic reaction (MgSO4•7H2O + H2O à Mg2+ + SO42- + 7H2O + H2O) was 16kJmol-1.

2. Accurately weigh out about 7.5 grams of anhydrous magnesium sulfate.

Some topics in this essay:
MgSO4•7H2O Error, MgSO4 Error, SULFATE Temperature, H2O MgSO4•7H2O, Container Method, Mass H2O, Practical Background, Variables Temperature, + h2o, Volume Water, magnesium sulfate, Mass MgSO4, enthalpy change, mgso4 +, + 7h2o, mg2+ + so42-, ∆t =, h2o à, à mg2+, so42- +, + so42-, + so42- +, h2o à mg2+, à mg2+ +, + h2o à,