Chemistry: Chemical Composition
You can use mass percent composition as a conversion factor between grams of a constituent element and grams of the compound. Write the conversion factor (including units) inherent in each mass percent composition. A) Water is 11.19% hydrogen by mass. B) Fructose, also known as fruit sugar, is 53.29% oxygen by mass. C) Octane, a component of gasoline, is 84.12% carbon by mass. D) Ethanol, the alcohol in alcoholic beverages, is 52.14% carbon by mass.
A) 11.19g H : 100 g H2O B) 53.29g O : 100 g fructose C) 84.12g C : 100g octane D) 52.14g C : 100g ethanol
What is the mass of 1 mol of atoms of each element? A) P B) Pt C) C D) Cr
A) 30.97g B) 195.08g C) 12.01g D) 52.00g
Why is chemical composition important?
Chemical composition lets us determine how much of a particular element is contained in a particular compound.
The subscripts in a chemical formula give relationships between moles of the constituent elements and moles of the compound. Explain why these subscripts DO NOT give relationships between grams of the constituent elements and grams of the compound.
Each element has a different atomic mass number. So, the subscripts that represent mole ratios cannot be used to represent the ratios of grams of a compound. The grams per mole of one element always differ from the grams per mole of a different element.
What is the mass of one mol of atoms for an element?
One mole of any element has a mass equal to its atomic mass in grams.
How are the empirical formula and the molecular formula of a compound related?
The empirical formula gives the smallest whole-number ratio of each type of atom. The molecular formula gives the specific number of each type of molecule in the molecule. The molecular formula is always a multiple of the empirical formula.
What is the empirical formula mass of a compound?
The empirical formula mass of a compound is the sum of the masses of all the atoms in the empirical formula.
How many atoms are in 1 mol of atoms?
There are 6.022X10^23 atoms in 1 mol of atoms.