5.50g of a certain Compound X, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 136./gmol, is burned completely in excess oxygen, and the mass of the products carefully measured: product mass carbon dioxide 14.24g water 2.91g Use this information to find the molecular formula of X.

The molecular formula is C8H8O2

Explanation:

Step 1: Data given

Mass of compound X = 5.50 grams

Mass of CO2 = 14.24 grams

Molar mass of CO2 = 44.01 g/mol

Mass of H2O = 2.91 grams

Molar mass H2O = 18.02 g/mol

Molar mass C = 12.01 g/mol

Molar mass O = 16.0 g/mol

Molar mass H = 1.01 g/mol

Molar mass of the compound = 136 g/mol

Step 2: Calculate moles CO2

Moles CO2 = 14.24 grams / 44.01 g/mol

Moles CO2 = 0.324 moles

Step 3: Calculate moles C

For 1 mol cO2 we have 1 mol C

For 0.324 moles CO2 we have 0.324 moles C

Step 4: Calculate mass C

Mass C = 0.324 moles * 12.01 g/mol

Mass C = 3.89 grams

Step 5: Calculate moles H2O

Moles H2O = 2.91 grams / 18.02 g/mol

Moles H2O = 0.161 moles

Step 6: Calculate moles H

For 1 mol H2O we have 2 moles H

For 0.161 moles H2O we have 2*0.161 = 0.322 moles H

Step 7: Calculate mass H

Mass H = 0.322 moles * 1.01 g/mol

Mass H = 0.325 grams

Step 8: Calculate mass O

Mass O = 5.50 grams - 3.89 grams - 0.325 grams

MAss O = 1.285 grams

Step 9: Calculate moles O

Moles O = 1.285 grams / 16.0 g/mol

Moles O = 0.0803 moles

Step 10: Calculate mol ratio

We divide by the smallest amount of moles

C: 0.324 moles / 0.0803 moles = 4

H: 0.322 moles / 0.0803 moles = 4

O: 0.0803 moles / 0.0803 moles = 1

The empirical formula is C4H4O

The molar mass of this empirical formula is 68 g/mol

Step 11: Calculate the molecular formula

We have to multiply the empirical formula by n

n = 136 g/mol / 68 g/mol

n = 2

We have to multiply the empirical formula by 2

Molecular formula = 2*(C4H4O) = C8H8O2

The molecular formula is C8H8O2

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them