I need help with these questions
1. Calculate the percentage by mass of potassium in potassium sulfate K2 SO4
2. calculate the percentage by mass of nitrogen in ammonium nitrate Nh4 No3
%K = (mass K/mass K2SO4)*100 = ?
For masses use atomic and molar masses.
Yes
Sure! I can help you with those questions.
To calculate the percentage by mass of an element in a compound, you need to follow a few steps:
1. Find the molar mass of the compound.
2. Find the molar mass of the element you are interested in.
3. Calculate the mass of the element in the compound.
4. Calculate the percentage by mass using the mass of the element and the molar mass of the compound.
Let's start with the first question:
1. Potassium sulfate (K2SO4) has the chemical formula K2SO4. To find the molar mass of potassium sulfate, you need to add up the individual molar masses of each element.
- The molar mass of potassium (K) is 39.10 g/mol.
- The molar mass of sulfur (S) is 32.07 g/mol.
- The molar mass of oxygen (O) is 16.00 g/mol.
So, the molar mass of potassium sulfate (K2SO4) is:
2 * (39.10 g/mol potassium) + 32.07 g/mol sulfur + 4 * (16.00 g/mol oxygen)
2. Now, let's calculate the molar mass of potassium sulfate:
Molar mass of K2SO4 = 2 * (39.10 g/mol) + 32.07 g/mol + 4 * (16.00 g/mol)
= 78.20 g/mol + 32.07 g/mol + 64.00 g/mol
= 174.27 g/mol
3. Next, we need to calculate the mass of potassium in potassium sulfate. Since the compound has two potassium atoms (K2), we can calculate the mass of potassium using its molar mass:
Mass of potassium = 2 * (39.10 g/mol)
= 78.20 g
4. Finally, we can calculate the percentage by mass of potassium in potassium sulfate:
Percentage by mass of potassium = (Mass of potassium / Molar mass of potassium sulfate) * 100%
= (78.20 g / 174.27 g) * 100%
≈ 44.85%
Therefore, the percentage by mass of potassium in potassium sulfate is approximately 44.85%.
Now, let's move on to the second question:
1. Ammonium nitrate (NH4NO3) has the chemical formula NH4NO3. To find the molar mass of ammonium nitrate, you need to add up the individual molar masses of each element.
- The molar mass of nitrogen (N) is 14.01 g/mol.
- The molar mass of hydrogen (H) is 1.01 g/mol.
- The molar mass of oxygen (O) is 16.00 g/mol.
2. The molar mass of ammonium nitrate (NH4NO3) is:
Molar mass of NH4NO3 = 14.01 g/mol nitrogen + 4 * (1.01 g/mol hydrogen) + 3 * (16.00 g/mol oxygen)
= 14.01 g/mol + 4.04 g/mol + 48.00 g/mol
= 66.05 g/mol
3. Let's calculate the mass of nitrogen in ammonium nitrate. Since the compound has one nitrogen atom (N), we can calculate the mass of nitrogen using its molar mass:
Mass of nitrogen = 1 * (14.01 g/mol)
= 14.01 g
4. Finally, we can calculate the percentage by mass of nitrogen in ammonium nitrate:
Percentage by mass of nitrogen = (Mass of nitrogen / Molar mass of ammonium nitrate) * 100%
= (14.01 g / 66.05 g) * 100%
≈ 21.20%
Therefore, the percentage by mass of nitrogen in ammonium nitrate is approximately 21.20%.
I hope this explanation helps! Let me know if you have any further questions.