Question

The molar mass of ammonium acetate is 77.083 g/mol. A student uses 0.100 mol of ammonium acetate in a chemical reaction. The student claims that the reaction uses
(0.100 mol)(77.083 g/mol)=7.71 g of ammonium acetate, which has
(7.71)(6.022×1023)=4.64×1024 molecules.

Answer 1

Is the student's claim correct?
To find the mass of 0.100 mol of ammonium acetate, we multiply the number of moles by the molar mass:
0.100 mol x 77.083 g/mol = 7.7083 g

So, the correct mass is 7.7083 g, not 7.71 g as stated by the student.

To find the number of molecules in 7.7083 g of ammonium acetate, we need to first convert the mass to moles:
7.7083 g / 77.083 g/mol = 0.1 mol

Now, we can use Avogadro's number to find the number of molecules:
0.1 mol x 6.022×10^23 molecules/mol = 6.022×10^22 molecules

Therefore, the correct number of molecules in 0.100 mol of ammonium acetate is 6.022×10^22, not 4.64×10^24 as claimed by the student.