0.717 g of a compound containing carbon, hydrogen, and oxygen is burned and found to produce 1.02 g CO2 and 0.624 g H2O. The molar mass of the compound is 124 g/mol.
(a) Write a chemical equation for the combustion of this unknown hydrocarbon.
(b) Determine the # of g and moles of carbon, hydrogen, and oxygen in the unknown hydrocarbon.
(c) Calculate the empirical formula.
(d) Calculate the molecular formula.
(e) Write the balanced equation for the combustion reaction.
You must know SOMETHING about this problem. Tell me what you know and I can help you through the remainder of it.
You know the mass of the hydrocarbon and the what mass of the products produced are as well as the mass of the compound.
part b. Convert g CO2 to g C, convert g H2O to g hydrogen, add the two and subtract from 0.717 to find g oxygen. Then I would find %C, %H, and %O. Take a 100 g sample and find moles. moles = grams/molar mass.
(a) To write a chemical equation for the combustion of the unknown hydrocarbon, we need to analyze the products formed. From the given information, we know that the compound produces CO2 and H2O when burned. Therefore, the combustion equation can be written as:
CxHyOz + O2 → CO2 + H2O
(b) To determine the amount of carbon, hydrogen, and oxygen in the unknown hydrocarbon, we can use the information about the mass of CO2 and H2O produced during combustion.
To find the number of grams of carbon in CO2, we need to know the molar mass of carbon. Since the molar mass of carbon is 12.01 g/mol, we can calculate the number of moles of carbon in CO2 by dividing the mass of CO2 by the molar mass of carbon:
Number of moles of carbon = mass of CO2 / molar mass of carbon
Number of moles of carbon = 1.02 g / 12.01 g/mol
Similarly, to find the number of grams of hydrogen in H2O, we need to know the molar mass of hydrogen. Since the molar mass of hydrogen is 1.01 g/mol, we can calculate the number of moles of hydrogen in H2O:
Number of moles of hydrogen = mass of H2O / molar mass of hydrogen
Number of moles of hydrogen = 0.624 g / 1.01 g/mol
To find the number of grams of oxygen in the unknown hydrocarbon, we can subtract the sum of the grams of carbon and hydrogen from the total mass of the compound:
Mass of oxygen = Total mass of the compound - mass of carbon - mass of hydrogen
Given the molar mass of the compound (124 g/mol) and using the definition of molar mass (molar mass = mass / moles), we can find the number of moles of the compound:
Number of moles of the compound = Total mass of the compound / molar mass of the compound
(c) To calculate the empirical formula, we need to determine the ratio of atoms in the compound. We can do this by dividing the moles of each element by the smallest number of moles among the elements.
Divide the number of moles of each element by the smallest number of moles (obtained from (b)) to get the ratio of atoms. Round the ratio to the nearest whole number to simplify it.
(d) To calculate the molecular formula, we need the molar mass of the empirical formula. Divide the molar mass of the compound by the molar mass of the empirical formula to obtain a whole number ratio. Multiply the subscripts of the empirical formula by this ratio to get the molecular formula.
(e) The balanced equation for the combustion reaction can be derived by using the information from the empirical formula. The equation will show the stoichiometric relationship between the reactants and products.