A sample of iron ore contains 1.02 x 10^24
Fe atoms and is found to be 69.94% Fe by mass. What is
the mass of the sample?
mols Fe = 1.02E24/6.02E23.
g Fe = mols Fe x atomic mass Fe.
%Fe = (g Fe/mass sample)*100
You have g Fe and %Fe, solve for mass sample.
To find the mass of the sample, you need to use the information provided about the number of Fe atoms and the percentage of Fe by mass.
First, we need to determine the molar mass of iron (Fe). The molar mass of Fe is approximately 55.845 g/mol. This means that 1 mole of Fe atoms weighs 55.845 grams.
Now, to find the mass of the sample, we can use the following steps:
Step 1: Convert the number of Fe atoms to moles of Fe.
To do this, divide the given number of Fe atoms (1.02 x 10^24) by Avogadro's number (6.022 x 10^23), which gives us the number of moles of Fe.
1.02 x 10^24 Fe atoms / 6.022 x 10^23 Fe atoms/mol = 1.695 moles of Fe
Step 2: Calculate the mass of Fe in the sample.
Multiply the number of moles of Fe by the molar mass of Fe to get the mass of Fe.
1.695 moles of Fe x 55.845 g/mol = 94.4 grams of Fe
Step 3: Determine the mass of the sample.
Since the sample is 69.94% Fe by mass, we can write the following equation:
100% (mass of sample) = 69.94% (mass of Fe)
Let's assume the mass of the sample is 'M' grams. Now, we can set up an equation as follows:
M x (69.94/100) = 94.4 grams of Fe
Solving for M:
M = (94.4) / (69.94/100)
M = 134.985 grams
Therefore, the mass of the sample is approximately 134.985 grams.