We have to solve this question using the stoichiometry of the reaction:
The equation of the reaction is;
According to the question;
Number of moles of CO2 released = 21.3 g/44 g/mol = 0.48 moles
From the stoichiometry of the reaction:
Since;
24 moles of CO2 released 15,026 KJ
0.48 moles of CO2 will release 0.48 * 15,026/24
= 301 KJ of heat.
The reaction between with calcium chloride can be shown as-
+
→
↓+2mCl. The molecular weight of
is 136.14g. The weight of sulfate ion is 96.06g. The molecular weight of
= (2×m + 96.06). From the reaction we can see that 1 mole of calcium chloride reacts with 1 moles
to produce 1 mole of calcium sulfate. Now 1.36g of calcium sulfate is equivalent to 1.36/136.14=9.989×
moles of calcium sulfate.
Thus, 9.989× moles of
reacts in this reaction.
Let assume the atomic mass of m is x thus the molecular weight of is 2x+96.
So we may write 9.989×× (2x+96) =1.42
Or, 2x + 96 = 142.146
Or, 2x = 46.146
Or, x = 23.073
Thus the atomic mass of m is 23.073. The atom (m) is sodium (Na).