Question

Assume Mass of NaCl = .9515 g NaCl

A. Calculate the moles of NaCl contained in the Sample.

B. Calcualte the moles of each element in NaCl.

C. Calculate the number of atms for each element in NaCl.

Answer 1

A)

Molar mass of NaCl,

MM = 1*MM(Na) + 1*MM(Cl)

= 1*22.99 + 1*35.45

= 58.44 g/mol

mass(NaCl)= 0.9515 g

number of mol of NaCl,

n = mass of NaCl/molar mass of NaCl

=(0.9515 g)/(58.44 g/mol)

= 0.01628 mol

Answer: 0.01628 mol

B)

NaCl is composed of Na and Cl

mol of Na = 0.01628 mol

mol of Cl = 0.01628 mol

C)

number of atoms of Na = number of mol of Na * 6.022*10^23

= 0.01628 * 6.022*10^23

= 9.804*10^21 atoms

number of atoms of Cl = number of mol of Cl * 6.022*10^23

= 0.01628 * 6.022*10^23

= 9.804*10^21 atoms