First, we write the reaction equation for the formation of HCl from hydrogen and chlorine:
H₂ + Cl₂ → 2HCl
Now, we substitute the values of the enthalpies, denoting that of the Cl-Cl bond by x:
435 + x = -92 + 2(431)
x = 335
The bond dissociation enthalpy for the Cl-Cl bond is 335 kJ/mol
Energy equals mass times the speed of light squared
First write down the chemical formula:
Fe(NO3)3 + K2S
Then, to determine the products use the AD+CB method to form your products:
A = Fe
B = (NO3)3
C = S
D = K2
Products: Fe2S3 + KNO3
Whole equation:
Fe(NO3)3 + K2S -> Fe2S3 + KNO3
Write the balanced chemical equation:
2 Fe(NO3)3 + 3 K2S -> Fe2S3 + 6 KNO3
Answer:
3.43 %
Explanation:
We need to calculate first the number of moles of CeO2 produced in the combustion. Given its formula we know how many moles of Ce atom are present. From there calculate the mass this number of moles this represent and then one can calculate the percentage.
0.1848 g CeO2 x 1 mol CeO2/172.114g = 0.00107 mol CeO2
0.00107 mol CeO2 x 1 mol Ce/ 1 mol CeO2 = 0.00107 mol Ce
.00107 mol Ce x 140.116 g Ce/ mol = 0.150 g Ce
0.150 g Ce/ 4.3718 g sample x 100 = 3.43 %