Answer to Question #350730 in General Chemistry for Alberto

Question

Calculate the value for the mass defect of a mole of the following:

a. Boron – 15 (isotopic mass = 15.031088 u)

b. Carbon – 14 (isotopic mass = 14.003241 u)

c. Nitrogen – 17 (isotopic mass = 17.008449 u)

Answer 1

1 u = 1.661*10^-24 g

According to Avogadro's law, 1 mole of a substance contains 6.02 * 10²³ particles (atoms, molecules).

To find the mass of 1 mole of isotope, multiply the given mass by 1.661 * 10^-24 and then multiply by the avogadro's number (6.02 * 10²³).

a.)

M = 15.031088 * 1.661*10^-24 * 6.02*10²³ = = 15 g

b.)

M = 14.003241 * 1.661*10^-24 * 6.02*10²³ = = 14 g

c.)

M = 17.008449 * 1.661*10^-24 * 6.02*10²³ =

= 17 g