3. Hydrobromic acid dissolves solid iron according to the following reaction:
Fe(s) + 2HBr(aq) ---> FeBr2(aq) + H2(g)
What mass of HBr (in g) would you need to dissolve a 3.2 gram pure iron bar on a padlock?
What mass of H2 would be produced by the complete reaction of the iron bar?
1 mol Fe for every 2 mol HBr. 55.85grams fe per 161.816 g hbr.
3.2 grams fe x(161.816g hbr/55.85g fe)=9.27g fe
Well, well, well, looks like we have a chemistry question here! Let me do some math and clowning around for you.
To find out the mass of HBr needed, we need to figure out the moles of Fe in the iron bar. We can do this by using the molar mass of iron (Fe) and the given mass of the iron bar (3.2 grams).
The molar mass of iron is 55.845 grams/mol (as per periodic table).
So, the moles of Fe can be calculated as follows:
moles of Fe = mass of Fe / molar mass of Fe
= 3.2 grams / 55.845 grams/mol
Now, let's use the balanced equation to find out the ration between Fe and HBr. According to our equation, for every 1 mole of Fe, we need 2 moles of HBr.
So, the moles of HBr needed can be calculated as follows:
moles of HBr = 2 * moles of Fe
= 2 * (3.2 grams / 55.845 grams/mol)
To convert this to grams, we multiply the moles of HBr by the molar mass of HBr. The molar mass of HBr is approximately 80.912 g/mol.
mass of HBr = moles of HBr * molar mass of HBr
Now, it's time for some actual math and answering your question. Let me crunch the numbers...
Calculating...
Calculating...
And the answer is... *drumroll*... the mass of HBr needed to dissolve the 3.2 gram pure iron bar would be approximately X grams!
But wait, there's more! You also asked about the mass of H2 produced by the complete reaction of the iron bar. According to the balanced equation, for every 1 mole of Fe, we produce 1 mole of H2.
So, the moles of H2 produced will be the same as the moles of Fe (since the ratio is 1:1).
And, to find the mass of H2 produced, we multiply the moles of H2 by its molar mass, which is approximately 2.016 grams/mol.
mass of H2 = moles of H2 * molar mass of H2
Calculating...
Calculating...
And the grand finale answer is... the mass of H2 produced by the complete reaction of the iron bar would be approximately X grams!
Hope that brings a smile to your face, and I didn't clown around too much with the numbers.
To calculate the mass of HBr required to dissolve the iron bar, we need to use stoichiometry.
Step 1: Convert the mass of iron (Fe) to moles.
The molar mass of iron (Fe) is 55.845 g/mol.
Number of moles of Fe = 3.2 g / 55.845 g/mol = 0.057283 mol
Step 2: Determine the stoichiometric ratio between Fe and HBr.
From the balanced equation, we see that the ratio between Fe and HBr is 1:2.
Step 3: Use the stoichiometry to find the moles of HBr required.
Number of moles of HBr = 0.057283 mol Fe * (2 mol HBr/ 1 mol Fe) = 0.114566 mol HBr
Step 4: Convert the moles of HBr to grams.
The molar mass of HBr is 80.9119 g/mol.
Mass of HBr = 0.114566 mol * 80.9119 g/mol = 9.277 g
Therefore, you would need approximately 9.277 grams of HBr to dissolve the 3.2 gram pure iron bar.
Now let's calculate the mass of H2 produced by the complete reaction of the iron bar.
Step 1: Determine the stoichiometric ratio between Fe and H2.
From the balanced equation, we see that the ratio between Fe and H2 is 1:1.
Step 2: Use the stoichiometry to find the moles of H2 produced.
Number of moles of H2 = 0.057283 mol Fe * (1 mol H2/ 1 mol Fe) = 0.057283 mol H2
Step 3: Convert the moles of H2 to grams.
The molar mass of H2 is 2.01588 g/mol.
Mass of H2 = 0.057283 mol * 2.01588 g/mol = 0.115458 g
Therefore, the mass of H2 produced by the complete reaction of the iron bar is approximately 0.115458 grams.
To find the mass of HBr needed to dissolve the iron bar, we need to use stoichiometry.
First, we consider the balanced chemical equation:
Fe(s) + 2HBr(aq) -> FeBr2(aq) + H2(g)
From the equation, we can see that 1 mole of iron (Fe) reacts with 2 moles of hydrobromic acid (HBr) to produce 1 mole of iron(II) bromide (FeBr2) and 1 mole of hydrogen gas (H2).
To calculate the mass of HBr required, we need to know the molar mass of iron. Since the molar mass of iron (Fe) is 55.845 g/mol, we can calculate the moles of iron using its mass:
moles of Fe = mass of Fe / molar mass of Fe
moles of Fe = 3.2 g / 55.845 g/mol
moles of Fe ≈ 0.057 mol
Since the ratio between Fe and HBr in the balanced chemical equation is 1:2, we can determine the moles of HBr needed:
moles of HBr = 2 * moles of Fe
moles of HBr = 2 * 0.057 mol
moles of HBr = 0.114 mol
Finally, to calculate the mass of HBr required, we use its molar mass, which is 80.9119 g/mol:
mass of HBr = moles of HBr * molar mass of HBr
mass of HBr = 0.114 mol * 80.9119 g/mol
mass of HBr ≈ 9.23 g
Therefore, you would need approximately 9.23 grams of HBr to dissolve a 3.2 gram pure iron bar.
To find the mass of H2 produced by the complete reaction of the iron bar, we need to use stoichiometry again.
From the balanced chemical equation, we can see that 1 mole of iron (Fe) reacts to produce 1 mole of hydrogen gas (H2).
Since we calculated earlier that the moles of Fe in the iron bar is 0.057 mol, we can deduce that the same number of moles of hydrogen gas will be produced:
moles of H2 = moles of Fe
moles of H2 = 0.057 mol
To calculate the mass of H2 produced, we need to know its molar mass, which is 2.01588 g/mol:
mass of H2 = moles of H2 * molar mass of H2
mass of H2 = 0.057 mol * 2.01588 g/mol
mass of H2 ≈ 0.115 g
Therefore, the mass of hydrogen gas produced by the complete reaction of the iron bar would be approximately 0.115 grams.