Question

The compound known as butylated hydroxytoluene, abbreviated as BHT, contains carbon, hydrogen, and oxygen. A 1.376 g sample of BHT was combusted in an oxygen rich environment to produce 4.122 g of CO2(g) and 1.350 g of H2O(g). Insert subscripts below to appropriately display the empirical formula of BHT.

Insert subscripts below to appropriately display the empirical formula of BHT

CHO

Answer 1

BHT is being burned in oxygen to form CO₂ and H₂O.

Amount of CO₂ formed = 4.122 g

Molar mass of CO₂ = 44.01 g/mol

Hence, the number of moles of CO₂ formed is

Note that each mole of CO₂ contains 1 mol of C that must have come from BHT.

Hence, the number of moles of C in BHT sample is

Atomic mass of C = 12.01 g/mol

Hence, the mass of C in sample of BHT is

Now, the amount of H₂O formed = 1.350 g

Molar mass of H₂O = 18.015 g/mol

Hence, the number of moles of H₂O formed is

Now, each mole of H₂O contains 2 moles of H that comes from the sample of BHT.

Hence, the number of moles of H in the sample of BHT is

Now, atomic mass of H = 1.00784 g/mol

Hence, the mass of H in the sample can be calculated as

Now, the mass of the sample is 1.376 g.

Hence, the mass of oxygen can be calculated as follows:

Atomic mass of O = 16.0 g/mol

Hence, the number of moles of O in the sample is

Now, we can take the ratio of the number of moles of elements and reduce them to lowest integers possible to get the empirical formula of BHT.

Hence, the empirical formula of BHT is .