Question

Using the below data:

Mass (g) of copper gluconate: 1.0 g

Mass (g) of wrapper: 0.6 g

Mass (g) of wrapper + Cu: 0.9 g

Mass (g) of Cu: 0.3 g

Mass (g) of gluconate: 0.7 g

1. Determine the chemical formula of copper gluconate?

2. Calculate the percent composition of copper and the percent composition of gluconate in the compound copper gluconate?

3. Create a Experimental Chemical Formula:

Answer 1

Mass of gluconate = 0.7g

And mass of Cu = 0.3g

Answer1.

Chemical formula of compound is determine from first convert into mole

Mole = given mass / molecular weight

Mole of Cu = 0.3g/63.546g/mole = 0.004720989519mole

Mole of gluconate is = 0.7g/195.127g/mole = 0.003588mole.

But we know that reaction is

Cu2+ + 2gluconate = Cu2+(gluconate)2

Hence above gluconate is limiting reagent and mole of Cu 2+ is use in half of the mole of gluconate = 0.003587407/2 = 0.001794mole

Or mass of copper use is = mole of Cu use in reaction * molecular weight of Cu

Mass of copper is = 0.001794mole *63.536g/mole = 0.11398g use

Hence chemical formula is Cu2+(gluconate)2

Answer 2

Mass of total compound is = 0.11398g of Cu + 0.7g mass of gluconate = 0.81398g

Mass percent of Cu = 0.11398g*100/0.81398g= 14.00275%

Mass percent of gluconate is = 0.7g*100/0.81398g = 85.99719%

Answer 3

Experimental chemical formula is same

Cu2+(gluconate)2