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

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.