Question

The mole is a counting number that allows scientists to describe how individual molecules and atoms react. If one mole of atoms or molecules is equal to 6.022 × 1023 atoms or molecules, how many molecules are in a 23.45 g sample of copper (II) hydroxide, Cu(OH)2? Express your answer to the correct number of significant figures. (MM of Cu(OH)2 is 97.562 g/mol). Be sure to show all steps completed to arrive at the
answer

Answer 1

Answer:

Mass of Cu(OH)2 = 23.45 g

Molar mass of Cu(OH)2 = 97.562 g/mol

Since we know,

Moles = Mass/Molar mass

\Rightarrow Moles = (23.45 g)/(97.562 g/mol) = 0.2404 moles

Since 1 mole of substance contains = 6.022 × 1023 molecules

So 0.2404 moles will contain = 0.2404*(6.022 × 1023 molecules) = 1.448 × 1023 molecules