The molar mass of CO2 can be calculated as follows;
CO2 — 12 + (16x2) = 12+ 32 = 44 g
Therefore molar mass of CO2 is 44 g/mol
In 44 g of CO2 there’s 1 mol of CO2
Then 1 g of CO2 there’s 1/44 mol of CO2
Therefore in 78.3 g of CO2 there’s — 1/44 x 78.3 =1.78 mol of CO2
Answer : The internal energy change is -2805.8 kJ/mol
Explanation :
First we have to calculate the heat gained by the calorimeter.

where,
q = heat gained = ?
c = specific heat = 
= final temperature = 
= initial temperature = 
Now put all the given values in the above formula, we get:


Now we have to calculate the enthalpy change during the reaction.

where,
= enthalpy change = ?
q = heat gained = 23.4 kJ
n = number of moles fructose = 

Therefore, the enthalpy change during the reaction is -2805.8 kJ/mole
Now we have to calculate the internal energy change for the combustion of 1.501 g of fructose.
Formula used :

or,

where,
= change in enthalpy = 
= change in internal energy = ?
= change in moles = 0 (from the reaction)
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get:




Therefore, the internal energy change is -2805.8 kJ/mol
Answer:
98.8
Explanation:
CsF + XeF6 --> CsXeF7
37.8g ................. ?g
37.8g CsF x (1 mol CsF / 151.9g CsF) x (1 mol CsXeF7 / 1 mol CsF) x (397.2g CsXeF7 / 1 mol CsXeF7) = 98.8g CsXeF7 .......... to three significant digits