5.5g of impure iron required 7.5cm3 of 3.0M HCL and give neutral solution calculate the purity of iron
Fe + 2HCl ==> FeCl2 + H2
millimoles HCl = mL x M = 7.5 mL x 3 M = 22.5
Use the coefficients in the balanced equation to convert to millimoles Fe in the sample = 1/2 * 22.5 = 11.3 or 0.0113 moles.
grams Fe = mols x molar mass = 0.0113 x 55.85 = 0.628 g
Then % purity = (g Fe/g sample)*100 = (0.628/5.5)*100 = ?
To calculate the purity of iron, we need to determine the number of moles of iron present in the impure sample. Here are the steps to follow:
Step 1: Calculate the number of moles of HCl used.
We have the volume and concentration of HCl.
Given:
Volume of HCl = 7.5 cm³
Concentration of HCl = 3.0 M
To find the number of moles of HCl, use the formula:
moles = concentration × volume (in liters)
Convert cm³ to liters by dividing by 1000:
Volume of HCl in liters = 7.5 cm³ / 1000 = 0.0075 L
Now we can calculate the moles of HCl:
moles of HCl = 3.0 M × 0.0075 L = 0.0225 moles
Step 2: Determine the moles of iron reacted with HCl.
From the balanced chemical equation between HCl and iron, we know that the stoichiometric ratio is 1:1. This means that for every 1 mole of HCl, 1 mole of iron is required.
moles of iron = moles of HCl = 0.0225 moles
Step 3: Calculate the molar mass of iron (Fe).
The molar mass of iron (Fe) is 55.845 g/mol.
Step 4: Calculate the mass of pure iron in the impure sample.
Given:
Mass of impure iron = 5.5 g
Using the formula:
mass = moles × molar mass
mass of pure iron = moles of iron × molar mass of iron
mass of pure iron = 0.0225 moles × 55.845 g/mol
mass of pure iron = 1.256 g
Step 5: Calculate the purity of iron.
To find the purity of iron, divide the mass of pure iron by the mass of the impure sample and multiply by 100:
purity of iron = (mass of pure iron / mass of impure iron) × 100
purity of iron = (1.256 g / 5.5 g) × 100
purity of iron = 22.836 %
Therefore, the purity of iron in the impure sample is approximately 22.836%.
To calculate the purity of iron in the given impure sample, we need to find the amount of pure iron present in the sample. Here's how we can approach the problem:
1. Determine the moles of HCl used:
- We are given the volume of HCl used, which is 7.5 cm^3.
- The molarity of HCl is 3.0 M, which represents 3.0 moles of HCl in 1 liter of solution.
- To find the moles of HCl used, we multiply the volume by the molarity: moles HCl = volume (in liters) x molarity.
- First, convert the volume from cm^3 to liters by dividing by 1000: 7.5 cm^3 ÷ 1000 = 0.0075 L.
- Now, calculate the moles of HCl used: moles HCl = 0.0075 L x 3.0 M = 0.0225 moles HCl.
2. Determine the moles of Fe reacted:
- The balanced chemical equation for the reaction between HCl and Fe is:
Fe + 2HCl → FeCl2 + H2
- From the equation, we see that one mole of Fe reacts with 2 moles of HCl.
- Therefore, the moles of Fe reacted is half the moles of HCl used, since the ratio is 1:2.
- Moles Fe = 0.0225 moles HCl ÷ 2 = 0.01125 moles Fe.
3. Calculate the molar mass of Fe:
- The molar mass of an element can be found from its atomic mass on the periodic table. For iron (Fe), the molar mass is approximately 55.85 g/mol.
4. Calculate the mass of pure Fe:
- Using the moles of Fe determined in step 2 and the molar mass of Fe determined in step 3, we can calculate the mass of pure Fe.
- Mass Fe = moles Fe x molar mass Fe = 0.01125 moles Fe x 55.85 g/mol = 0.628 g Fe.
5. Calculate the purity of iron:
- The purity of iron is given as the ratio of the mass of pure iron to the mass of the impure sample, expressed as a percentage.
- Purity of iron = (mass Fe / mass impure sample) x 100%
- Mass impure sample = 5.5 g (given in the question)
- Purity of iron = (0.628 g Fe / 5.5 g impure sample) x 100% = 11.42%
Therefore, the purity of the iron in the given impure sample is approximately 11.42%.