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Please clearly show steps! Thank you. A. Determine the percent composition of a

ID: 545927 • Letter: P

Question

Please clearly show steps! Thank you.

A. Determine the percent composition of a compound formed from 0.500g of tin reacting with oxygen and forming 0.635 g of the oxide.

B. Determine the empirical and molecular formulas for a compound that has a molar mass of 62g/mol and is 38.7%C, 9.74%H and 51.6%O by mass.

C. Determine the empirical and molecular formula for a compound that is 31.42% S, 31.35% O and 37.23%F and has a molar mass of 102.1g/mol.

D. Determine the number of oxygen atoms in a 45.6 oz. sample of aluminum sulfate.

Explanation / Answer

B)

Element            %by mass         atomic wt.        relative number            simple ratio

   C                        38.7                12                   38.7/12 = 3.225       3.225/3.225 = 1.0

   H                       9.74                 1.0                   9.74/1.0= 9.74         9.74/3.225 =   3.0

   O                       51.6                16                   51.6/16 =3.225         3.225/3.225 = 1.0

        Emperical formula = CH3O

    Emperical formula mass = 12+3+16 = 31

Molar mass = 62 grams

n= molar mass/emperical formula mass = 62/31 = 2

Molecular formula= nxemperical formula = 2xCH3O = C2H6O2

Molecular formula = C2H6O2

C).

Element           % by mass      atomic wt            relative number               simple ratio

S                   31,42                   32                  31.42/32 = 0.98                 0.98/0.98 = 1.0

O                  31.35                    16                  31.35/16 = 1.959             1.959/0.98= 1.99 = 2.0

F                    37.23                    19                  37.23/19 = 1.959              1.959/0.98 = 1.99 = 2.0

          Emperical formula= SO2F2

emperical formula mass = 32+32+38=102

Molar mass = 102.1 grams

n= molar mass/emperical formula mass = 102.1/102= 1.0

n= 1.0

Molecular formula = nxemperical formula= 1xSO2F2

Molecular formula = SO2F2.

D).mass of Al2(SO4)3 = 45.6gr ams

molar mass of Al2(SO4)3 =342.15 grams/mole

342.15 grams of Al2(SO4)3 contains = 12x6.023x10^23 atoms of Oxygen

45.6 grams of Al2(SO4)3contains= ?

                            = 12x6.023x10^23x45.6/342.15 = 9.63x10^23 atoms of oxygen