The work done to expand a gas is 121 J. During the gas expansion, 402 J of heat is absorbed by the gas sample. Calculate the change in internal energy (ΔE) of the gas in kJ. [Hint: ΔE = q + w. Make sure to check the sign conventions.]

ΔE = kJ.

3.50

Explanation:

because the heat of engine cause a gas

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"