Question

How many molecules are in 5.50 grams of AgNO3?

a 6.14 x 1022 molecules
b 0.032 molecules
c 3.22 x 1022 molecules
d 1.93 x 1022 molecules
e 8.67 x 1021 molecules

Answer 1

1.95*10²² molecules are in 5.50 grams of AgNO₃

Step-by-step explanation:

Being the molar mass of the elements:

• Ag: 107.87 g/mole
• N: 14 g/mole
• O: 16 g/mole

then the molar mass of the compound is:

AgNO₃: 107.87 g/mole + 14 g/mole + 3*16 g/mole= 169.87 g/mole

Then you can apply the following rule of three: if 169.87 grams of the compound are present in 1 mole, 5.50 grams will be present in how many moles?

`moles=(5.50 grams*1 mole)/(169.87 grams)`

moles= 0.0324

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.

You can apply the following rule of three: if by definition of Avogadro's Number 1 mole of the substance contains 6.023 * 10²³ molecules, 0.0324 moles how many molecules will it have?

`molecules=(0.0324 moles*6.023*10^(23) molecules)/(1 mole)`

molecules=1.95*10²²

1.95*10²² molecules are in 5.50 grams of AgNO₃