Question

How many atoms are in 0.750 moles of zinc?

Answer 1

Hint To calculate the number of atoms first we have to calculate the number of moles of the given element as the number of moles is already given, then the mass can easily be calculated. A mole is generally used as a unit for the number of atoms or molecules or particles of a material.

Complete step by step solution:
The mole is a measurement or it is the basic unit which helps to calculate the amount of substance present in the given sample. 1 mole of a number is equal to Avogadro’s constant ${{N}_{A}}$ .
Number of mol is calculated by ratio of given mass to the molar mass.
Number of mol of zinc = $\dfrac{\text{given mass}}{\text{molar mass}}$
Given,
Number of moles = 0.750 moles
Molar mass of zinc= 65 amu
Number of atoms of zinc =
$0.750\times 6.022\times {{10}^{23}}=4.52\times {{10}^{23}}$ .

Additional information:
Atomic number is the number of protons present in the nucleus of every atom of that element. Mass number is the sum of protons and neutrons present in the nucleus of the atom. Protons and neutrons are collectively known as nucleons.

Note: 1 mole= $6.022X{{10}^{23}}$ particle or atoms or molecules or electrons or
protons etc. The number of the constituent particles of atoms such as molecules or atoms or ions present in a given sample is related with the mass of the substance present in the sample using Avogadro's number. The SI unit of Avogadro’s number is inverse of mole i.e. $mol{{e}^{-1}}$
Avogadro’s number is dimensionless. It also helps to relate the molar volume of a substance to the average volume which is occupied by one of the particles.