Question

2. Calculate the number of particles in each of the following:

a. 72 g of Magnesium atoms.

b. 5 moles of Sodium atoms. get brainliest by doing step by step​

Answer 1

Answer:

a) 18.066 × 10^23 atoms b) 30.11 × 10^23

Explanation:

a)

To find number of atoms in 72 grams of Mg, first convert gram mass into number of moles then convert moles into number of atoms

Gram mass of Mg = m = 72 g

molar mass of Mg = M = 24 g/mol

number of moles = gram mass / molar mass

n= m/M

number of atoms= number of moles × Avogadro's Number

N = n × NA

= 3 × 6.022 × 10^23

= 18.066 × 10^23

b)

number of moles= n= 5 moles

Number of atoms = N = n × NA

= 5 × 6.022 × 10^23

= 30.11 × 10^23

n = 72/24

= 3 moles