Chemistry help please

Question

What is the mass in gram 5.00 mol of barium chloride

Answer 1

Use the atomic weight of barium chloride and dimensional analysis to solve this:.

Atomic weight of barium chloride:

Barium 137.327

Chlorine 35.45

Since Ba sits in the second group it's charge is +2, while Chlorine is a -1 so combine you would have BaCl2. For the atomic weight you would need 2 chlorine atoms to balance the molecule and make it so that there is no charge or so that it is charge neutral.

BaCl2 atomic weight:

Barium: 137.327

Chlorine: 35.45 x 2= 70.9

172.77g/mol

Now take the moles given use dimensional analysis and get grams:

5 mol *172.77g/mol

Notice how moles cancel top to bottom and you are left with grams in the numerator which are your units.

863.88 g or 864g for sig fig purposes.

Answer 2

Barium chloride = BaCl₂

Molar mass BaCl2 = 137.3 + (2 x 35.45) = 208.2 g / mol

5.00 mols x 208.2 g / mol = 1040 g (3 sig. figs.)