Question

A pure solid consists of either (I) sodium chloride (Nacl) (II) copper carbonate (Cuo3) (III) Sodium carbonate (Na2Co3). 1.06 gram of the solid contains 0.01 mole of compound what is the chemical identity of the solid?

Answer 1

To determine the chemical identity of the solid, we need to calculate the molar mass of each compound and compare it to the given data.

I) Sodium chloride (NaCl):
Molar mass = 22.99 g/mol (Na) + 35.45 g/mol (Cl) = 58.44 g/mol

II) Copper carbonate (CuCO3):
Molar mass = 63.55 g/mol (Cu) + 12.01 g/mol (C) + 3(16.00 g/mol) (O) = 123.55 g/mol

III) Sodium carbonate (Na2CO3):
Molar mass = 2(22.99 g/mol) (Na) + 12.01 g/mol (C) + 3(16.00 g/mol) (O) = 105.99 g/mol

Given data:
Mass of solid = 1.06 g
Number of moles of compound = 0.01 mol

Now, we can calculate the molar mass of the solid using the formula:

Molar mass = (Mass of solid) / (Number of moles of compound)

Molar mass = 1.06 g / 0.01 mol = 106 g/mol

Comparing the calculated molar mass (106 g/mol) to the molar masses of the compounds:

- Sodium chloride (NaCl): 58.44 g/mol
- Copper carbonate (CuCO3): 123.55 g/mol
- Sodium carbonate (Na2CO3): 105.99 g/mol

The closest match to the calculated molar mass is Sodium carbonate (Na2CO3). Therefore, the chemical identity of the solid is Sodium carbonate (Na2CO3).