Question

What is the mass, in grams, of 1.20×1021 molecules of aspirin, c9h8o4?

Answer 1

The mass in grams of 1.20 x10^21 molecules of asprin is 0.359 grams

calculation

find the number of moles of aspirin by use of Avogadro's law that is 1 mole =6.02 x10^23 molecules

what of 1 .20 x10^21 molecules

= (1 mole x 1.20 x10 ^21 molecules)/6.02 x10^23 molecules)= 1.993 x10^-3 moles

mass of aspirin= moles x molar mass

molar mass of aspirin = (12 x9)+(1 x8) +(16x4)=180 g/mol

mass= 1.993 x10^-3 moles x180 g/mol = 0.359 grams

Answer 2

Answer: The mass of given number of molecules of aspirin is 0.359 grams.

Step-by-step explanation:

We are given:

Number of molecules of aspirin =
`1.20* 10^(21)`

We know that:

Molar mass of aspirin
`(C_9H_8O_4)` = 180.16 g/mol

According to mole concept:

`6.022* 10^(23)` number of molecules are contained in 1 mole of a compound

Also,
`6.022* 10^(23)` number of molecules of aspirin has a mass of 180.16 grams

So,
`1.20* 10^(21)` number of molecules will have a mass of
`(180.16)/(6.022* 10^(23))* 1.20* 10^(21)=0.359g`

Hence, the mass of given number of molecules of aspirin is 0.359 grams.