maryanne

A 1.50g sample of NH4NO3(s) is added to 35.0g of water in a foam cup and stirred intil it dissolves. The temperature of the solution drops from 22.7 to 19.4 degrees celcius. What is the heat of dissolution of NH4NO3, expressed in kJ/mol NH4NO3?

i have one more question: I know this one has to do with hess's law but i'm not sure of how to get the enthalpy of vaporization from this? Clculate the enthalpy of vaporization of solid potassium bromide to a gas of ions, the process KBr--->K{+1}(g)+Br{-1...

What is the total resistance in a parallel circuit with a 10 ohm lamp and a 15 ohm lamp?

An aluminum engine block has a volume of 4.86 L and a mass of 12.75 kg. What is the density of the aluminum in grams per cubic centimeter?

to DrBob222 wouldn't it be like this then 4.86L/12.75kg*1000cm^3/1L*(1kg/1000g)^3

28.06 mL to grams

23. Lois built a rectangular flower bed. She used four boards for the border of the flower bed. Two of the boards were 4 feet long. The other boards were 8 feet long. a. What was the area of the flower bed using these boards? b. She decided to cut each bo...

I got: delta H= 482.79J 482.79/150gNH4NO3 x 80gNH4NO3/mol NH4NO3 =2574.88J/mol =2.575 kJ/mol Is this right?

i have one more question: I know this one has to do with hess's law but i'm not sure of how to get the enthalpy of vaporization? Clculate the enthalpy of vaporization of solid potassium bromide to a gas of ions, the process KBr--->K{+1}(g)+Br{-1}(g), from...

ya you're right i accidently put the wrong value in!

thanx so much!

I am unable to make the figure (with both boards) to begin with...