A certain mass(m) of an impure iron sample of 40% purity ,is treated with an excess of HCl to give H2 that occupies 44.8 L at s.t.p ( Vm=22.4) where the yeild of the reaction is 0.8.
A) calculate m.
B) deduce the mass of HCl reacted.
Thanks in advance!!
Fe+2HCl>>FeCl2?+H2
so moles of H2=44.8/22.4=2 moles, which then idicates 2/.8 moles of Fe
m=(2/.8) * mole mass Fe
mass HCl= (4/.8)*molemassHCl
A) To calculate the mass of the impure iron sample (m), we need to consider that the yield of the reaction is 0.8, which means that only 80% of the iron reacts.
Given that the impure iron sample is 40% pure, it means that only 40% of the mass of the sample is actually iron.
First, we calculate the mass of pure iron in the impure sample:
Mass of pure iron = 40% of m = 0.4m
Since only 80% of the iron reacts, the mass of iron that reacts is:
Mass of iron reacted = 0.8 * Mass of pure iron = 0.8 * 0.4m = 0.32m
At STP, one mole of H2 occupies 22.4 L. Therefore, the number of moles of H2 can be calculated as follows:
Number of moles of H2 = Volume of H2 / Volume of 1 mole of H2 = 44.8 L / 22.4 L = 2 moles
According to the balanced chemical equation, 1 mole of iron reacts with 1 mole of HCl to produce 1 mole of H2. Therefore, the number of moles of iron reacted is also 2.
Now, we can set up a ratio between the number of moles of iron reacted and its mass:
2 moles / 0.32m = 1 mole / m
Solving for m:
2 * m = 0.32m
2m = 0.32m
0.68m = 0
m = 0
Thus, the mass of the impure iron sample is 0 g.
B) To deduce the mass of HCl reacted, we need to consider the stoichiometry of the reaction.
From the balanced chemical equation, we know that 1 mole of HCl reacts with 1 mole of iron to produce 1 mole of H2.
Since the number of moles of iron reacted is 2, the number of moles of HCl reacted is also 2.
To calculate the mass of HCl, we need to use its molar mass. The molar mass of HCl is 36.5 g/mol.
Mass of HCl reacted = Number of moles of HCl * Molar mass of HCl
Mass of HCl reacted = 2 moles * 36.5 g/mol
Mass of HCl reacted = 73 g
Therefore, the mass of HCl reacted is 73 g.
To solve this problem, we need to calculate the mass of the impure iron sample (m) and the mass of HCl reacted.
A) To calculate m, we can use the equation:
moles of impure iron = moles of hydrogen gas
First, let's find the number of moles of hydrogen gas produced:
moles of hydrogen gas = volume of hydrogen gas / molar volume at STP
moles of hydrogen gas = 44.8 L / 22.4 L/mol
moles of hydrogen gas = 2 moles
Since the yield of the reaction is given as 0.8, we need to calculate the total moles of impure iron:
moles of impure iron = moles of hydrogen gas / yield
moles of impure iron = 2 moles / 0.8
moles of impure iron = 2.5 moles
Finally, we can calculate the mass of the impure iron sample using the percent purity:
mass of impure iron sample = moles of impure iron * molar mass of iron
molar mass of iron = 55.85 g/mol (approximate)
mass of impure iron sample = 2.5 moles * 55.85 g/mol
mass of impure iron sample = 139.63 g (approximately)
So, the mass of the impure iron sample is approximately 139.63 grams.
B) To deduce the mass of HCl reacted, we first need to find the number of moles of HCl used.
From the balanced chemical equation:
Fe + 2HCl -> FeCl2 + H2
We can see that 1 mole of iron reacts with 2 moles of HCl. Since the moles of iron is 2.5 (from previous calculation), the moles of HCl used can be calculated as follows:
moles of HCl = moles of iron * 2
moles of HCl = 2.5 moles * 2
moles of HCl = 5 moles
Finally, we can calculate the mass of HCl reacted using the molar mass of HCl:
molar mass of HCl = 36.46 g/mol (approximate)
mass of HCl reacted = moles of HCl * molar mass of HCl
mass of HCl reacted = 5 moles * 36.46 g/mol
mass of HCl reacted = 182.3 g (approximately)
Therefore, the mass of HCl reacted is approximately 182.3 grams.