<u>Answer:</u> Moles of iron for the given amount is 17.90 moles.
<u>Explanation:</u>
We are given 1 kg of iron and we need to find the moles of it. To calculate the moles, we use the following equation:
Mass of iron given = 1kg = 1000 grams (Conversion Factor: 1 kg = 1000g)
Molar mass of iron = 55.85g/mol
Putting values in above equation, we get:
Hence, moles of iron for the given amount is 17.90 moles.
Answer:
Percentage of copper = 88%
Explanation:
Given data:
Mass of copper = 51.2 g
Mass of tin = 6.84 g
Percentage of copper = ?
Solution:
Formula:
Percentage of copper = mass of copper / total mass × 100
Now we will determine the total mass:
Total mass = mass of copper + mass of tin
Total mass = 51.2 g + 6.84 g
Total mass = 58.04 g
Now we will calculate the percentage of copper.
Percentage of copper = 51.2 g / 58.04 g × 100
Percentage of copper = 0.88 × 100
Percentage of copper = 88%
Easy!
All you have to do is look at the formula.
Lead Sulfide is PbS
Lead Oxide is PbO
Sulfur Dioxide is SO₂
Oxygen is O₂
You would need to balance out the equation, so it would be PbS + O₂ --> PbO + SO₂.
We can balance this out with the following. 2PbS + 2O₂ --> 2PbO + SO₂.
So 0.500 moles of oxygen would be the same conversion rate for PbO so it would also be 0.500 moles of lead oxide (PbO)
Q = mCΔT
Q is heat, m is mass, C is specific heat, and ΔT is change in temp
Q = (50g)(.21)(500 degrees) = 5250 calories
Molality is defined as the number of moles of solute in 1 kg of solvent.
since density and volume has been given we can calculate the mass of water
mass = density x volume
mass = 1.00 g/mL x 1620 mL = 1620 g
number of moles of glucose - 257 g / 180 g/mol = 1.43 mol
number of moles of glucose in 1620 g - 1.43 mol
therefore number of moles in 1000 g - 1.43 mol / 1.620 kg = 0.883 mol/kg
therefore molality is 0.883 mol/kg