Question

Convert 3.27 g of Ni2O3 to grams of Ni

Convert 5.75x1024 molecules of Ni2O3 to grams of O2

Answer 1

2 Ni2O3 (s) $\rightarrow$ 4 Ni(s) + 3 O2 (g)

(1) Given : 3.27 g of Ni2O3

Molar mass of Ni2O3 = 165.3 g/mol

Moles of Ni2O3 = given mass / molar mass

= 3.27 / 165.3

= 0.0197 mole

According to above balanced reaction

2 moles of Ni2O3 react to form 4 moles of Ni

0.0197 moles of Ni2O3 react to form =(4 x 0.0197)/2

= 0.0394 mole of Ni

To convert in grams

Mass of Ni = moles x molar mass

Molar mass of Ni = 58.6 g/mol

So, mass of Ni = 0.0394 x 58.6

= 2.30 g of Ni

(2) Given : 5.75 x 1024 molecules of Ni2O3

6.023 x 1023 molecules = 1 mole

5.75 x 1024 molecules = (1 x 5.75 x 1024)/6.023 x 1023

= 9.54 moles of Ni2O3

According to above reaction

2 moles of Ni2O3 react to form 3 moles of O2

9.54 moles of Ni2O3 react to form = (3 x 9.54 )/2

= 14.31 moles of O2

Molas mass of O2 = 32 g/mol

So, mass of O2 = moles x molar mass

= 457.9 g of O2