how many grams of zinc chloride could be formed from the reaction of 3.57 g of zinc with excess HCL
7.45
7.4422
Zn + 2HCl ==> H2 + ZnCl2
mols Zn = grams/molar mass
Using the coefficients in the balanced equation, convert mols Zn to mols ZnCl2.
Now convert mols ZnCl2 to grams. g = mols x molar mass.
To determine the grams of zinc chloride formed, we need to first write and balance the chemical equation for the reaction between zinc and hydrochloric acid (HCl).
The balanced equation is:
Zn + 2HCl → ZnCl2 + H2
From the balanced equation, we see that 1 mole of zinc reacts with 2 moles of hydrochloric acid to form 1 mole of zinc chloride.
1. Calculate the number of moles of zinc (Zn):
Given mass of zinc = 3.57 g
Molar mass of zinc (Zn) = 65.38 g/mol
moles of Zn = mass of Zn / molar mass of Zn
= 3.57 g / 65.38 g/mol
2. Determine the limiting reactant:
In this case, zinc is given in excess, so it is not limiting the reaction. The HCl is in excess.
3. Since zinc is in excess, we need to calculate the moles of HCl that react with the given amount of zinc:
As per the balanced equation, the ratio of moles of HCl to moles of Zn is 2:1.
Moles of HCl = 2 × moles of Zn
4. Calculate the mass of zinc chloride formed:
The molar mass of zinc chloride (ZnCl2) is 136.29 g/mol.
mass of ZnCl2 = moles of ZnCl2 × molar mass of ZnCl2
Now, let's calculate the results:
1. moles of Zn = 3.57 g / 65.38 g/mol = 0.0547 mol
2. Moles of HCl = 2 × moles of Zn = 2 × 0.0547 = 0.1094 mol
3. mass of ZnCl2 = moles of ZnCl2 × molar mass of ZnCl2
= 0.0547 mol × 136.29 g/mol
= 7.46 g
Therefore, the mass of zinc chloride formed from the reaction of 3.57 g of zinc with excess HCl is 7.46 grams.