1. How many molecules of barium hydroxide, Ba(OH)2 are there in 21.9 grams of
barium hydroxide?
A. 6.022 x 1023 molecules Ba(OH)2
B. 7.7 x 1022 molecules Ba(OH)2
C. 6.23 x 1021 molecules Ba(OH)2
D. 5.93 x 1021 molecules Ba(OH)2

molecules of

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.

To calculate the moles, we use the equation:

1 mole of contains =   molecules

0.128 mole of contains =   molecules

Thus there are molecules of

gas

explanation:

smoke is the matter of a gas