Calculate the mass of Fe(NH4)2(SO4)26H2O in your unknown sample. Show you work.
Average mass of unknown sample:1.0714g
1.42 g
how did you calculate it? @oobleck
I'm just guessing but I think oobleck made up a number. I don't see enough information there to have any idea of what you're doing.
To calculate the mass of Fe(NH4)2(SO4)2·6H2O in your unknown sample, you need to use the information provided. Here are the steps to find the mass:
Step 1: Find the molar mass of Fe(NH4)2(SO4)2·6H2O
Fe: 1 atom x atomic mass of Fe = 1 x 55.845 g/mol
N: 2 atoms x atomic mass of N = 2 x 14.007 g/mol
H: 8 atoms x atomic mass of H = 8 x 1.008 g/mol
S: 2 atoms x atomic mass of S = 2 x 32.06 g/mol
O: 18 atoms x atomic mass of O = 18 x 16.00 g/mol (6 from SO4 and 12 from H2O)
Total molar mass of Fe(NH4)2(SO4)2·6H2O = sum of the above values
Step 2: Calculate the number of moles of Fe(NH4)2(SO4)2·6H2O in your sample
Number of moles = mass of the sample / molar mass of Fe(NH4)2(SO4)2·6H2O
Step 3: Calculate the mass of Fe(NH4)2(SO4)2·6H2O in your sample
Mass = number of moles x molar mass of Fe(NH4)2(SO4)2·6H2O
Let's work through an example calculation using the given average mass of the unknown sample:
Step 1: Find the molar mass of Fe(NH4)2(SO4)2·6H2O
Molar mass of Fe(NH4)2(SO4)2·6H2O = (1 x 55.845) + (2 x 14.007) + (8 x 1.008) + (2 x 32.06) + (18 x 16.00) g/mol
Step 2: Calculate the number of moles of Fe(NH4)2(SO4)2·6H2O in your sample
Number of moles = 1.0714 g / molar mass of Fe(NH4)2(SO4)2·6H2O g/mol
Step 3: Calculate the mass of Fe(NH4)2(SO4)2·6H2O in your sample
Mass = number of moles x molar mass of Fe(NH4)2(SO4)2·6H2O g
By following these calculations, you will be able to determine the mass of Fe(NH4)2(SO4)2·6H2O in your unknown sample.