1. Make a Prediction
2. Fill both beakers with water
3. Dissolve salt in one of the beakers
4. Place both in the freezer and observe
5. Write a report
(Always make the prediction first! That's a hypothesis!)
The molecular formula of calcium oxide - CaO
The molar mass of CaO - 40 + 16 = 56 g/mol
Which means that 1 mol weighs 56 g
Therefore 56 g of CaO is - 1 mol
Then 89.23 g is equivalent to - 1/56 x 89.23 = 1.6 mol of CaO
Answer : The enthalpy change for the reaction is, 201.9 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The balanced reaction of
will be,

The intermediate balanced chemical reaction will be,
(1)

(2)

(3)

(4)

Now we will multiply the reaction 1 by 2, revere the reaction 2, reverse and half the reaction 3 and 4 then adding all the equations, we get :
(1)

(2)

(3)

(4)

The expression for enthalpy of the reaction will be,



Therefore, the enthalpy change for the reaction is, 201.9 kJ
Answer : 1721.72 g/qt are in 18.2 g/cL
Explanation :
As we are given: 18.2 g/cL
Now we have to convert 18.2 g/cL to g/qt.
Conversions used are:
(1) 1 L = 100 cL
(2) 1 L = 1000 mL
(3) 1 qt = 946 qt
The conversion expression will be:


Therefore, 1721.72 g/qt are in 18.2 g/cL