Do Now - AP - % Comp of a Substance

Front

What is an empirical formula?

Back

The empirical formula is the simplest whole-number ratio of moles of elements in a compound.

Front

How do you determine the empirical formula from combustion data?

Back

By calculating the moles of each element from the mass of products formed during combustion and finding the simplest ratio.

Front

Which pair has the same empirical formula: NaCrO4 and Na2Cr2O7, or C2H4O2 and C6H12O6?

Back

C2H4O2 and C6H12O6 have the same empirical formula.

Front

What is the molecular formula if the empirical formula is CCl2 and the molecular mass is 160 g/mole?

Back

The molecular formula is C2Cl4.

Front

How do you calculate the empirical formula from mass data?

Back

Convert the mass of each element to moles, then divide by the smallest number of moles to find the simplest ratio.

Front

What is the empirical formula of a compound containing 2.70 g of C and 15.95 g of Cl?

Back

The empirical formula is CCl2.

Front

Define molecular formula.

Back

The molecular formula shows the actual number of atoms of each element in a molecule.

Front

What is the difference between empirical and molecular formulas?

Back

The empirical formula represents the simplest ratio of elements, while the molecular formula shows the actual number of atoms.

Front

How do you find the molecular formula from the empirical formula?

Back

Multiply the subscripts in the empirical formula by a whole number to match the molecular mass.

Front

What is the empirical formula of a compound with a molecular formula of C6H12O6?

Back

The empirical formula is C2H6O.