What mass of HBr (in g) would you need to dissolve a 3.7 −g pure iron bar on a padlock?
Well, you could try dissolving the iron bar with HBr, but you might end up with a padlock that's really "keyed" out. But if you're willing to take the risk, here's the scoop:
To calculate the mass of HBr you would need, we first need to find the molar mass of HBr. Hydrogen (H) has a molar mass of approximately 1 g/mol, and bromine (Br) has a molar mass of approximately 80 g/mol. So, the molar mass of HBr is roughly 81 g/mol.
Since we have the mass of the iron bar (3.7 g), let's assume it reacts completely with HBr. The balanced chemical equation for the reaction between iron (Fe) and HBr is:
Fe + 2HBr → FeBr2 + H2
From the equation, we can see that the stoichiometry is 1:2 between iron and HBr, meaning 1 mol of Fe reacts with 2 mol of HBr.
Now, let's convert the mass of Fe to moles. The molar mass of iron is approximately 56 g/mol. So, 3.7 g of Fe is equal to 3.7 g / 56 g/mol ≈ 0.066 mol.
Since the stoichiometry is 2:1 between HBr and Fe, we need twice as many moles of HBr as moles of Fe. So, we need 2 × 0.066 mol = 0.132 mol of HBr.
Finally, let's convert the moles of HBr to grams. The molar mass of HBr is approximately 81 g/mol. Therefore, the mass of HBr required would be 0.132 mol × 81 g/mol ≈ 10.692 g.
So, approximately 10.692 grams of HBr would be needed to dissolve the iron bar. But be careful, dissolving an iron bar can be a pretty "brutal" experiment!
To determine the mass of HBr needed to dissolve the iron bar, we must first understand the chemical reaction involved. In this case, iron (Fe) reacts with hydrobromic acid (HBr) to form iron(II) bromide (FeBr2) and hydrogen gas (H2).
The balanced chemical equation for this reaction is:
Fe + 2HBr -> FeBr2 + H2
From the equation, we can see that the ratio of Fe to HBr is 1:2.
To calculate the mass of HBr required, we need to use the molar mass of iron (Fe) from the periodic table. The molar mass of iron is approximately 55.85 g/mol.
So, let's calculate the mass of HBr:
1. Calculate the molar mass of HBr:
- Hydrogen (H) has a molar mass of approximately 1.01 g/mol.
- Bromine (Br) has a molar mass of approximately 79.90 g/mol.
Molar mass of HBr = 1.01 g/mol + 79.90 g/mol = 80.91 g/mol
2. Use the molar ratio to determine the mass of HBr needed:
- From the balanced equation, the molar ratio of Fe to HBr is 1:2.
Mass of HBr = (Molar mass of HBr / Molar mass of Fe) * Mass of Fe
= (80.91 g/mol / 55.85 g/mol) * 3.7 g
≈ 5.37 g
Therefore, you would need approximately 5.37 g of HBr to dissolve a 3.7 g pure iron bar on a padlock.
To determine the mass of HBr required to dissolve the iron bar, we need to consider the balanced chemical equation between iron (Fe) and hydrogen bromide (HBr).
The balanced chemical equation for the reaction between iron and hydrogen bromide is:
Fe(s) + 2HBr(aq) → FeBr2(aq) + H2(g)
From the balanced equation, we can see that 1 mole of iron (Fe) reacts with 2 moles of hydrogen bromide (HBr) to form 1 mole of iron bromide (FeBr2) and 1 mole of hydrogen gas (H2).
To solve the problem, follow these steps:
Step 1: Calculate the molar mass of iron (Fe):
The molar mass of iron (Fe) is 55.845 g/mol.
Step 2: Convert the mass of the iron bar to moles:
Divide the mass of the iron bar (3.7 g) by the molar mass of iron (55.845 g/mol) to convert the mass to moles:
3.7 g Fe × (1 mol Fe / 55.845 g Fe) = 0.066 moles Fe
Step 3: Determine the stoichiometry between iron (Fe) and hydrogen bromide (HBr):
From the balanced equation, we know that 1 mole of Fe reacts with 2 moles of HBr. Therefore, the number of moles of HBr required is twice the number of moles of Fe:
0.066 moles Fe × (2 moles HBr / 1 mole Fe) = 0.132 moles HBr
Step 4: Convert moles of HBr to grams:
Multiply the number of moles of HBr (0.132 moles) by the molar mass of HBr to convert the moles to grams:
0.132 moles HBr × (80.912 g HBr / 1 mol HBr) = 10.699 g HBr
Therefore, you would need approximately 10.699 grams of HBr to dissolve a 3.7-gram pure iron bar.
dissolve? You are kidding.
The reaction would be 2 HBr + Fe>>Fe(Br)2 + H2
so you need twice the moles of HBr as is moles Fe.
Moles Fe= 3.7/55.8
Moles HBr= twice that.
Mass HBr= molesHBr* (1+80)