Answer:
0.84 mol
Explanation:
Given data:
Moles of ZnCl₂ produced = ?
Mass of Zn = 55.0 g
Solution:
Chemical equation:
2HCl + Zn → ZnCl₂ + H₂
Number of moles of Zn:
Number of moles = mass / molar mass
Number of moles = 55.0 g/ 65.38 g/mol
Number of moles = 0.84 mol
Now we will compare the moles of Zn with ZnCl₂ from balance chemical equation.
Zn : ZnCl₂
1 : 1
0.84 : 0.84
So from 55 g of Zn 0.84 moles of zinc chloride will be produced.
Answer:
C2H4O
Explanation:
C H O
54.54/12 9.09/1 36.37/16
4.545 9.09 2.27
4.545/2.27 9.09/2.27 2.27/2.27
2.00 4.00 1
Empirical formula is C2H4O
Answer:
264 g/mol
Explanation:
#electrons equal #protons = 106
Plus 1 charge => m protons = 106 + 1 = 107
Mass number: 107 + 157 = 264 g/mol
You have 0.50 mol of NH3 and 0.20 mol of NH4+ to start (NH4Cl dissolves completely), given the molarity and 1.0 L solution.
30.0 mL of 1.0 M HCl is 0.0300 mol of HCl. This will react with the NH3 to produced 0.030 mol of NH4+.
You now have 0.47 mol NH3 and 0.23 mol NH4+. Now use the Henderson-Hasselbach equation to calculate your pH. The equation says to use concentration of acid and base, but you can just use the moles of them because it doesn’t make a difference.
pH = pKa + log(base/acid)
pKa = 14 - pKb = 14 - 4.75 = 9.25
pH = 9.25 + log(0.47/0.23) = 9.56
