Assume that you were assigned BaCl2 in lab. The water in your test tube weighed 21.797 g. Following the procedure in the lab manual, you determined that freezing point of water is 0.02oC. You weighed out 1.168 g of salt and added it to the original test tube, then determined that the freezing point was -0.33oC. Based on these experimental parameters, calculate the van't Hoff factor for BaCl2.

Van't Hoff factor for is 1.15

Explanation:

Depression in freezing point:

where,

= freezing point of solution =

= freezing point of water =  

= freezing point constant of water =

m = molality

i = Van't Hoff factor = ?

= mass of solute = 1.168 g

= mass of solvent (water) = 21.797 g

= molar mass of solute = 208 g/mol

Now put all the given values in the above formula, we get:

Thus van't Hoff factor for is 1.15

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.