Question

Using the information in the table, calculate the number of moles in a 7.89 kg sample of aspirin
(C9H8O4).
Write your answer using three significant figures.

Answer 1

Answer:

43.7mol

Explanation:

$?mol = 7.86kg * \frac{1000g}{1kg} *\frac{1mol}{180g}$

Above is dimensional analysis method. Write what you are trying to find with the question mark and write your given info on the other side of the equal sign. Follow the units and pay attention to them cancelling out. You should have your answer unit by the end.

the 180g came from the table with masses times the chemical formula all added together. Below is exact formula.

hydrogen mass(hydrogen amount) + carbon mass(carbon amount) + oxygen mass(oxygen amount)

1g(8)+12g(9)+16g(4)=180g

180g is 1 mole of $C_{9} H_{8} O_{4}$