Please explain all answers 1) Phenol was the first antiseptic. It has the chemic

Question

Please explain all answers

1) Phenol was the first antiseptic. It has the chemical composition 76.57% C, 6.43% H, 17.00% O. The molecular weight of phenol was determined by mass spectroscopy to be 94.114 g/mol. What is the molecular formula for phenol?

2) A 3.5514 g of a chromium oxide was found to contain 2.4299 g of chromium and 1.1215 g oxygen. What is the empirical formula for this chromium oxide?

3) Phosphoric acid is produced by the reaction of calcium phosphate, Ca3(PO4)2, with sulfuric acid. How much phosphoric acid can one make from exactly one US ton (2000 lbs) of calcium phosphate?

Explanation / Answer

moles of C = 76.57 / 12 = 6.381

moles of H = 6.43 / 1 = 6.43

moles of O = 17 /16 = 1.0625

C                H               O

6.381           6.43           1.0625

6                     6                 1

empirical formula = C6H6O

empirical formula mass = 94.114 g

n = molar mass / empirical formula mass

n = 1

molecular formula = n x empirical formula

                              = C6H6O

2)

A 3.5514 g of a chromium oxide was found to contain 2.4299 g of chromium and 1.1215 g oxygen. What is the empirical formula for this chromium oxide?

moles of Cr = 2.4299 / 52 = 0.0467

moles of O = 1.1215 / 16 = 0.0701

moles ratio : Cr   :   O = 1 : 1.5 = 1 : 3/2

empirical formula = Cr2O3

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects