If all the energy obtained from burning 1.17 pounds of propane is used to heat water, how many kilograms of wa?

OKay so basically you have one equation with two steps.
You need to convert the pounds to grams. I used an online conversion calculator,
Then you find the moles of propane.
Next you multiply (mol C3H8)(Enthalpy of C3H8)
Enthalpy of 1 mol C3H8=-2043.9kJ
This is the q value. But it is in kJ you want J
Plug q into the water equation and solve.
q=(grams of water)(4.184J/g*mole)(temp change)
Don't forget to divide your final answer by 1000 to get kg instead of grams and that should be your answer.

For your answer i got 253 kg with sigfigs