Please help!! I am so lost!!
calculate the number of moles in 100g each:
PbCl2
K2SO4
HNO3
CH3CH2OH
V2O5
Thankyou!!
mass(g) / molmass(g/mol) = moles
So, for each compound, find its mol mass and divide into 100g.
HNO3 has mass 1+14+3*16 = 63
So, 100g / 63g/mol = 1.59 moles
Suppose I told you to find the number of bean bags in 100 lbs. You'd first have to find out how much one bean bag weighs, then see how many times that goes into 100. Same thing here.
Thanks!!
Of course! I can help you with that.
To calculate the number of moles, you need to use the formula:
Number of moles = Mass / Molar mass
Let's go step by step for each compound:
1. PbCl2:
- Find the molar mass of PbCl2 by adding the atomic masses of each element. The atomic mass of Pb is 207.2 g/mol, and for Cl, it is 35.5 g/mol. Therefore, the molar mass of PbCl2 is 207.2 + (2 * 35.5) = 278.2 g/mol.
- Now, divide the mass given (100 g) by the molar mass (278.2 g/mol) to find the number of moles of PbCl2.
2. K2SO4:
- Calculate the molar mass by summing the atomic masses of each element. The atomic mass of K is 39.1 g/mol, S is 32.1 g/mol, and O is 16.0 g/mol. The molar mass of K2SO4 is then (2 * 39.1) + 32.1 + (4 * 16.0) = 174.3 g/mol.
- Divide the given mass (100 g) by the molar mass (174.3 g/mol) to determine the number of moles of K2SO4.
3. HNO3:
- Add up the atomic masses of H, N, and O to calculate the molar mass. H has a mass of 1.0 g/mol, N is 14.0 g/mol, and O is 16.0 g/mol. The molar mass of HNO3 is 1.0 + 14.0 + (3 * 16.0) = 63.0 g/mol.
- Divide the given mass (100 g) by the molar mass (63.0 g/mol) to find the number of moles of HNO3.
4. CH3CH2OH:
- Calculate the molar mass by summing the atomic masses of each element. C has a mass of 12.0 g/mol, H is 1.0 g/mol, and O is 16.0 g/mol. The molar mass of CH3CH2OH is (2 * 12.0) + (6 * 1.0) + 16.0 = 46.0 g/mol.
- Divide the given mass (100 g) by the molar mass (46.0 g/mol) to determine the number of moles of CH3CH2OH.
5. V2O5:
- Add the atomic masses of V and O to calculate the molar mass. V has a mass of 50.9 g/mol, and O is 16.0 g/mol. The molar mass of V2O5 is (2 * 50.9) + (5 * 16.0) = 181.9 g/mol.
- Divide the given mass (100 g) by the molar mass (181.9 g/mol) to find the number of moles of V2O5.
Now you can apply this calculation to each compound and find the number of moles in 100 g of each substance.