Answer
a $ NH_3 $ : 17.03 g/mol
b. $ N_2H_4 $ : 32.05 g/mol
c. $ (NH_4)_2Cr_2O_7 $ : 252.08 g/mol
Work Step by Step
a.
- 1 blue spheres: 1 Nitrogen atom.
- 3 white spheres: 3 Hydrogen atoms.
$ NH_3 $ : ( 1.008 $\times$ 3 )+ ( 14.01 $\times$ 1 )= 17.03 g/mol
b.
- 2 blue spheres: 2 Nitrogen atom.
- 4 white spheres: 4 Hydrogen atoms.
$ N_2H_4 $ : ( 1.008 $\times$ 4 )+ ( 14.01 $\times$ 2 )= 32.05 g/mol
c.$ (NH_4)_2Cr_2O_7 $ : ( 52.00 $\times$ 2 )+ ( 1.008 $\times$ 4 $\times$ 2 )+ ( 14.01 $\times$ 2 )+ ( 16.00 $\times$ 7 )= 252.08 g/mol
