Question

How can you find the number of particles in a salt packet of known mass?Place the tiles to complete the equation to convert from grams to particles. Refer to the mole road map to determine the correct conversion factors. Use the space below to take notes or make calculations if needed.

Answer 1

First, you need to transform grams of NaCl into moles of NaCl. For this, you will divide by its molar mass. If you divide a fraction, If you divide a fraction, it is inverted and multiplied. So first you have:

0.75 g NaCl x 1 mol NaCl / 58.4 g/mol NaCl = 1.28 x 10^-2 moles

Now you need to use the avogrado's constant to find the number of particles. The avogrado's constant value is 6.02x10^23 mol^-1.

So you have:

0.75 g NaCl x 1 mol NaCl / 58.4 g/mol NaCl x 6.02 x 10^23 particles NaCl / 1 mol NaCl = 7.73 x 10^21 particles of NaCl