The Grass Doctor

question is in details?

in a chemistry experiment to investigate the properties of a fertilizer, 10 g of NH2CONH2 is dissolved in 150 ml of water in a simple calorimeter. a temperature change from 20.4 C to 16.7 C is measured. calculate the molar enthalpy of solution for the ferilizer urea.

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2. Sounds right to me!!!!!
3. It's 17.5 temperature change a undivided of events that equal more then the caorlimetere in the end it'll have a 11g NHC with will not dissolced in the 150 ml of water.
4. We can see by the decrease in temperature of water that the reaction must be endothermic. We must determine the molar mass of the fertilizer. Molar Mass = 1.01 * 4 + 12.01 + 16.00 + 14.01*2 = 60.07g/mol We can now figure out how many moles of feritlizer we have. = 10g / 60.07g/mol = 0.166 mol Now we need to determine the amount of energy required to change water from 20.4C to 16.7C Water has a specific heat capacity of 4.19J/(goC) = 4.19 J/(goC) * 150g * (16.7-20.4)oC = -2325J = -2.33kJ Be careful about the signs, we aren't done yet. We know that 0.166 mols of fertilizer dissolved in water required the water to give off 2.33kJ. This energy was absorbed by the solution of the fertilizer. Because the reaction was endothermic, the enthalpy will be positive. = 2.33kJ/0.166mol = + 14.0kJ/mol You can check to make sure that I haven't made a mistake. I hope this helps you.