Download presentation
Presentation is loading. Please wait.
Published byJustin Pierce Modified over 8 years ago
1
How many atoms are in 3.6 mol of calcium? How many moles are in 1.45 x 10 24 atoms of sodium? What is the molar mass of K 2 SO 4 ? How many grams of CO are in 2.9 moles? How many moles is 236 g of NaOH? What is the mass of 7.6 x 10 23 atoms of KF? How many atoms are in 192 g of MgCl 2 ?
2
Pg. 73
3
Formulas tell us ratios of the number of atoms in the compound Ex. Freon is CCl 2 F 2 There is 1 C, 2 Cl, and 2 F We can figure out how many moles of one element there are in a given compound. Moles of compound x # of atoms of element 1 mole of compound
4
How many moles of F are in 5.50 moles of CCl 2 F 2 ? Calculate the number of moles of each element in 1.25 moles of C 6 H 12 O 6.
5
First, find the molar mass of the compound Multiply the mass of one element by its subscript Divide the mass of one element by the total mass in the compound Multiply by 100 Ex. H 2 O
7
Determine the percent by mass of each element in the compound CaCl 2.
8
Calculate the percent composition of each of the following element in the compound Ga 2 (SO 4 ) 3. If you have a 100g sample of MgO and 60% is magnesium and 40% is oxygen, how many grams of each do you have?
9
Pg. 75
10
Empirical formula = the formula with the smallest whole number ratio of the elements If you know the percent composition of the element, divide the amount of that element by its molar mass. This tells you # moles of that element. If it is written as a percent, assume there are 100 g of the compound If the numbers aren’t whole numbers, divide by the smaller value If the numbers still aren’t whole numbers, multiply by the smallest factor that will make them whole
11
Compound with 40.05% S and 59.95% O Determine the empirical formula for methyl acetate which has the following chemical make up: 48.64% C, 8.16% H, and 43.20% O.
12
Sometimes the empirical formula is the same for two different compounds When that happens, you take the experimentally determined molar mass of the compound and divide it by the mass of the empirical formula This gives you a whole number (n) that must be multiplied into the empirical formula
13
Succinic acid is composed of 40.68% C, 5.08% H and 54.24% oxygen and has a molar mass of 118.1 g/mol. Determine the empirical and molecular formulas for succinic acid.
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.