# Can you determine the empirical formulas for the following compounds (showing the work)? 2.  A 6.21 gram sample of a compound contains 4.54 grams of iodine and the rest is cerium. 3.  The...

Can you determine the empirical formulas for the following compounds (showing the work)?

2.  A 6.21 gram sample of a compound contains 4.54 grams of iodine and the rest is cerium.

3.  The compound benzoic acid contains 68.8% carbon, 4.95% hydrogen, and 26.2% oxygen by mass.

4.  Freons are gaseous compounds used in refrigeration.  One particular Freon contains 9.93% carbon, 58.6% chlorine, and 31.4% fluorine by mass.

5.  A germicidal compound is found to be 33% sodium, 36% arsenic, and 31% oxygen.  What is the formula of this compound?  What is this compounds name?

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted on

The compound is made up of iodine and cerium. A 6.21 gram sample of the compound contains 4.54 grams of iodine and 1.67 grams. The molar mass of iodine is 126.9 g/mole and the molar mass of cerium is 140.1 g/mole

1.67 g of cerium is equivalent to 0.012 moles and 4.54 g of iodine is equivalent to 0.036 moles. For each mole of cerium, the compound has 3 moles of iodine.

This gives the empirical formula of the compound as `CeI_3`

parama9000 | Student, Grade 11 | (Level 1) Valedictorian

Posted on

CeI3

Yojana_Thapa | Student, Grade 10 | (Level 1) Valedictorian

Posted on

2.  A 6.21 gram sample of a compound contains 4.54 grams of iodine and the rest is cerium.

• Iodine: 4.54g

Atomic Mass: 127

# of moles of element: (4.54/127)= 0.035

Simplest ratio of moles: (0.035/0.011)= 3

• Cerium: 1.67g

Atomic Mass: 140

# of moles of element: (1.67/140)= 0.011

Simplest ratio of moles: (0.011/0.011) = 1

Empirical Formula = I3Ce

3.  The compound benzoic acid contains 68.8% carbon, 4.95% hydrogen, and 26.2% oxygen by mass.

• Carbon: 68.8%

Atomic Mass: 12

# of moles of element: (68.8/12)= 6

Simplest ratio of moles: (6/2) = (3 x 2) = 6

• Hydrogen: 4.95%

Atomic Mass: 1

# of moles of element: (4.95/1)= 5

Simplest ratio of moles: (5/2) = (2.5 x 2) = 5

• Oxygen: 26.2%

Atomic Mass: 16

# of moles of element: (26.2/16)= 2

Simplest ratio of moles: (2/2) = (1 x 2) = 2

Empirical Formula = C6H5O2

5.  A germicidal compound is found to be 33% sodium, 36% arsenic, and 31% oxygen.  What is the formula of this compound?  What is this compounds name?

• Sodium: 33%

Atomic Mass: 23

# of moles of element: (33/23)= 1.434

Simplest ratio of moles: (1.434/0.48) = 3

• Arsenic: 36%

Atomic Mass: 75

# of moles of element: (36/75)= 0.48

Simplest ratio of moles: (0.48/0.48) = 1

• Oxygen: 31%

Atomic Mass: 16

# of moles of element: (31/16)= 1.937

Simplest ratio of moles: (1.937/0.48) = 4

Empirical Formula = Na3ASO4 (Sodium Arsenate)