Question

using your own experimental values for moles of copper along with the knowledge that all of the possible unknowns have one mole of copper per mole of salt, calculate the experimental molar mass for the salt you believe you had for an unknown. calculate the percent error between the experimental and actual molar masses of the salts.

Answer 1

Experimental molar mass of salt = 100 g/mol

Percent error = -16.67%

To calculate the experimental molar mass of the salt, you need the experimental values for the moles of copper and the ratio between the moles of copper and the moles of salt.

Let's say you have 0.5 moles of copper in your experiment. If the ratio of moles of copper to moles of salt is 1:1, then you also have 0.5 moles of salt.

Now, to calculate the experimental molar mass of the salt, you divide the mass of the salt by the moles of salt. Let's assume the mass of the salt is 50 grams.

Experimental molar mass of salt = mass of salt / moles of salt

Experimental molar mass of salt = 50 g / 0.5 mol

Experimental molar mass of salt = 100 g/mol

Now, to calculate the percent error between the experimental and actual molar masses of the salt, you need the actual molar mass of the salt. Let's assume the actual molar mass is 120 g/mol.

Percent error = (experimental molar mass - actual molar mass) / actual molar mass * 100

Percent error = (100 g/mol - 120 g/mol) / 120 g/mol * 100

Percent error = -20 g/mol / 120 g/mol * 100

Percent error = -0.1667 * 100

Percent error = -16.67%

The negative sign in the percent error indicates that the experimental molar mass is lower than the actual molar mass. The percent error of -16.67% indicates that the experimental molar mass is 16.67% lower than the actual molar mass.