Transcript Document

Problem 1
Total
• 4000 yellow legos
• 2000 black legos
• 1200 blue legos
• 400 orange legos
• Write analogous empirical and molecular formula
• YwBkxBuyOz
Hint 1: How did you decide on the lowest ratio of Boys to Girls in the people demo?
Problem 1
Total
• 4000 yellow legos
• 2000 black legos
• 1200 blue legos
• 400 orange legos
• If there were four butterflies, what is the “molecular
formula”, aka how many of each colored lego was
present in the butterfly.
• YwBkxBuyOz
Problem 2:
• The compound sold under the name Prozac is 66.01% C, 5.87% H, 18.43% F,
4.53% N and 5.17% O. What is the empirical formula?
Hint:
Get numbers of each atom.
Compare them (divide by the
smallest) like we did in the
example with your fellow
students moving around.
Problem 3:
A folk medicine used in the Anhui province of China to treat acute dysentery is cha-tiao-qi, a preparation
of the leaves of Acer ginnala. Reaction of one of the active ingredients in cha-tiao-qi with water yields
gallic acid, a powerful antidysenteric agent. Gallic acid is known to contain carbon, hydrogen and oxygen.
A chemist wanting to determine the molecular formula of gallic acid burned 1.000g of the compound in
an elemental analyzer. The products of the combustion were 1.811 g of CO2 and 0.3172 g of H2O.
a) Determine the empirical formula of the compound .
b) The molar mass was found to be 170.12 g/mol.
What is the molecular formula of gallic acid ?
c) What would the formula be if the mass was found
to be 510 g/mol ?
Problem 3
A folk medicine used in the Anhui province of China to treat acute dysentery is cha-tiao-qi, a preparation
of the leaves of Acer ginnala. Reaction of one of the active ingredients in cha-tiao-qi with water yields
gallic acid, a powerful antidysenteric agent. Gallic acid is known to contain carbon, hydrogen and oxygen.
A chemist wanting to determine the molecular formula of gallic acid burned 1.000g of the compound in
an elemental analyzer. The products of the combustion were 1.811 g of CO2 and 0.3172 g of H2O.
a) Determine the empirical formula of the compound .
How many mols of C are present?
How many mols of H are present?
How many mols of O are present?
What is the empirical formul?
Problem 3
A folk medicine used in the Anhui province of China to treat acute dysentery is cha-tiao-qi, a preparation
of the leaves of Acer ginnala. Reaction of one of the active ingredients in cha-tiao-qi with water yields
gallic acid, a powerful antidysenteric agent. Gallic acid is known to contain carbon, hydrogen and oxygen.
A chemist wanting to determine the molecular formula of gallic acid burned 1.000g of the compound in
an elemental analyzer. The products of the combustion were 1.811 g of CO2 and 0.3172 g of H2O.
b) The molar mass was found to be 170.12 g/mol.
What is the molecular formula of gallic acid ?
If the empirical formula is C7H6O5. What is the
empirical mass?
Problem 3
A folk medicine used in the Anhui province of China to treat acute dysentery is cha-tiao-qi, a preparation
of the leaves of Acer ginnala. Reaction of one of the active ingredients in cha-tiao-qi with water yields
gallic acid, a powerful antidysenteric agent. Gallic acid is known to contain carbon, hydrogen and oxygen.
A chemist wanting to determine the molecular formula of gallic acid burned 1.000g of the compound in
an elemental analyzer. The products of the combustion were 1.811 g of CO2 and 0.3172 g of H2O.
c) What would the formula be if the mass was found
to be 510 g/mol ?