What the mole?!? You don’t scare me, Chapter 11!

What the mole?!?What the mole?!?

You don’t scare me, Chapter You don’t scare me, Chapter 11!11!

For each question asked:For each question asked:

►Copy question (These are on the blog Copy question (These are on the blog if you aren’t fast enough in class.)if you aren’t fast enough in class.)

►Determine which type of problem is Determine which type of problem is being askedbeing asked

►Set up problem (Solving is for Set up problem (Solving is for homework.)homework.)

#1#1

►How many molecules are collected in How many molecules are collected in 6.50 moles of CuCl6.50 moles of CuCl2 2 ??

#2#2

►48.675g of bismuth represents how 48.675g of bismuth represents how many atoms of bismuth?many atoms of bismuth?

#3#3

►What is the molar mass of chlorine What is the molar mass of chlorine gas?gas?

Be careful of the formula!!Be careful of the formula!!

#4#4

►Dr. Bubba (Dr. Bubba (chemist extraordinairechemist extraordinaire) ) wants to use .450 mol of aluminum wants to use .450 mol of aluminum sulfide. How much should be sulfide. How much should be measured onto the balance?measured onto the balance?

#5#5

►A compound has a molar mass of A compound has a molar mass of 110.1g/mol. Its percent composition 110.1g/mol. Its percent composition seems to indicate an empirical formula seems to indicate an empirical formula of Cof C33HH33O.O.

► Is that the correct formula for the Is that the correct formula for the compound?compound?

#6#6

►What percent of gypsum is actually What percent of gypsum is actually calcium?calcium?

(gypsum = CaSO(gypsum = CaSO44 · 2H· 2H22O)O)

#7#7

►What percent of gypsum is actually What percent of gypsum is actually water?water?

#8#8

►How many moles of iron (III) nitrate How many moles of iron (III) nitrate are represented by 43.56mg of the are represented by 43.56mg of the salt?salt?

(Hey! Is that a milligram?)(Hey! Is that a milligram?)

#9#9

►What is the average mass of 50 atoms What is the average mass of 50 atoms of sulfur?of sulfur?

#10#10

►Styrene is 92.25% carbon and 7.75% Styrene is 92.25% carbon and 7.75% hydrogen. What empirical formula hydrogen. What empirical formula does that indicate?does that indicate?

#11#11

►The molar mass of styrene is The molar mass of styrene is 104g/mol. What must be the 104g/mol. What must be the molecular formula?molecular formula?

(Yep, use #10 to figure this out.)(Yep, use #10 to figure this out.)

#12#12

►How many molecules of COHow many molecules of CO22 are in are in 44.10g of carbon dioxide?44.10g of carbon dioxide?

#13#13

►What percent of anhydrous copper (II) What percent of anhydrous copper (II) sulfate is oxygen?sulfate is oxygen?

#14#14

►What is the empirical formula of a What is the empirical formula of a compound containing:compound containing: 10.52g nickel10.52g nickel 4.38g carbon4.38g carbon 5.10g nitrogen5.10g nitrogen

#15#15

►One billion molecules of water are in One billion molecules of water are in your hand; how many moles of your hand; how many moles of molecules are you holding?molecules are you holding?

Fine’Fine’

►So, how did you do?So, how did you do?

►E-mail your results to me for bonus E-mail your results to me for bonus points! (Shhhh, it’s our secret!!)points! (Shhhh, it’s our secret!!)

Valid only til 2/10/11……Valid only til 2/10/11……

#1#1

►How many molecules are collected in How many molecules are collected in 6.50 moles of CuCl6.50 moles of CuCl2 2 ??

► 6.50mol CuCl6.50mol CuCl22 (6.022 x 10(6.022 x 102323 molecules) molecules)

► ( 1 mole CuCl( 1 mole CuCl22))

► 3.91 x 103.91 x 102424 molecules CuCl molecules CuCl22

#2#2

►48.675g of bismuth represents how 48.675g of bismuth represents how many atoms of bismuth?many atoms of bismuth?

►48.675g 48.675g (6.022 x 10(6.022 x 102323 atoms Bi) atoms Bi)► (208.98038g Bi)(208.98038g Bi)

►1.403 x 101.403 x 102323 atoms of Bi atoms of Bi

#3#3

►What is the molar mass of chlorine What is the molar mass of chlorine gas?gas?

Be careful of the formula!! Chlorine is Be careful of the formula!! Chlorine is ClCl22!!!!

►2(35.453g/mol) = 70.906g/mol Cl2(35.453g/mol) = 70.906g/mol Cl22

#4#4

►Dr. Bubba (chemist extraordinaire) Dr. Bubba (chemist extraordinaire) wants to use .450 mol of aluminum wants to use .450 mol of aluminum sulfide. How much should be sulfide. How much should be measured onto the balance?measured onto the balance?

►0.450mol Al0.450mol Al22SS33 (150.162g Al(150.162g Al22SS33))► (1 mol Al(1 mol Al22SS33))

►67.6 g Al67.6 g Al22SS33

#5#5►A compound has a molar mass of A compound has a molar mass of

110.1g/mol. Its percent composition 110.1g/mol. Its percent composition seems to indicate an empirical formula of seems to indicate an empirical formula of CC33HH33O.O.

► Is that the correct formula for the Is that the correct formula for the compound?compound?

CC33HH33O = 55.056g/mol which is only O = 55.056g/mol which is only halfhalf of the of the required 110.1g/molrequired 110.1g/mol

►No, CNo, C66HH66OO22 is the correct molecular is the correct molecular formula.formula.

#6#6

►What percent of gypsum is actually What percent of gypsum is actually calcium?calcium?

(gypsum = CaSO(gypsum = CaSO44 · 2H· 2H22O)O)

►Ca Ca x 100 x 100►CaSOCaSO44·2H·2H22OO

►40.08/172.18x100 = 40.08/172.18x100 = 23.28% Ca23.28% Ca

#7#7

►What percent of gypsum is actually What percent of gypsum is actually water?water?

►2H2H22O O x 100 x 100

►CaSOCaSO44·2H·2H22OO

►36.030/172.18x100 = 36.030/172.18x100 = 20.926% H20.926% H22OO

#8#8

►How many moles of iron (III) nitrate are How many moles of iron (III) nitrate are represented by 43.56mg of the salt?represented by 43.56mg of the salt?

(Hey! Is that a milligram?)(Hey! Is that a milligram?)

► 43.56mg Fe(NO43.56mg Fe(NO33))33 (10(10-3-3 g) g) (1 mole) (1 mole) = =

► (1 mg) (241.859g)(1 mg) (241.859g)

► 1.801 x 101.801 x 10-4-4 moles Fe(NO moles Fe(NO33))33

#9#9

►What is the average mass of 50 atoms of What is the average mass of 50 atoms of sulfur?sulfur?

► 50 atoms S 50 atoms S (32.066 g S)(32.066 g S) = =► (6.022 x 10(6.022 x 102323 atoms S) atoms S)

► 2.662 x 102.662 x 10-21-21g Sg S (Note: 4 sig figs) (Note: 4 sig figs)► (Note: the smallest mass unit we saw was (Note: the smallest mass unit we saw was

the attogram which is 10the attogram which is 10-18-18))

#10#10

►Styrene is 92.25% carbon and 7.75% Styrene is 92.25% carbon and 7.75% hydrogen. What empirical formula hydrogen. What empirical formula does that indicate?does that indicate?

►CHCH

#11#11

►The molar mass of styrene is The molar mass of styrene is 104g/mol. What must be the 104g/mol. What must be the molecular formula?molecular formula?

(Yep, use #10 to figure this out.)(Yep, use #10 to figure this out.)

►CH = 13.019g/mol AND 104/13 = 8CH = 13.019g/mol AND 104/13 = 8►Therefore, styrene is Therefore, styrene is CC88HH88

#12#12

►How many molecules of COHow many molecules of CO22 are in are in 44.10g of carbon dioxide?44.10g of carbon dioxide?

►6.022 x 106.022 x 102323 molecules CO molecules CO22

►The mass given happens to be the molar The mass given happens to be the molar mass which IS the mass of Avogadro’s mass which IS the mass of Avogadro’s number for COnumber for CO2 2 This one of those that if This one of those that if you recognize that number as its molar you recognize that number as its molar mass, you don’t even have to calculate.mass, you don’t even have to calculate.

#13#13

►What percent of anhydrous copper (II) What percent of anhydrous copper (II) sulfate is oxygen?sulfate is oxygen?

►4O/CuSO4O/CuSO44 x 100 x 100

►40.096% oxygen40.096% oxygen

#14#14

►What is the empirical formula of a compound What is the empirical formula of a compound containing:containing: 10.52g nickel10.52g nickel 4.38g carbon4.38g carbon 5.10g nitrogen5.10g nitrogen

►Ni(CN)Ni(CN)2 2 nickel (II) cyanidenickel (II) cyanide

►Most of you would have CORRECTLY put Most of you would have CORRECTLY put NiCNiC22NN22 Try to recognize polyatomic ions with Try to recognize polyatomic ions with metals.metals.

#15#15

►One billion molecules of water are in One billion molecules of water are in your hand; how many moles of your hand; how many moles of molecules are you holding?molecules are you holding?

►1 x 101 x 1099 molecules H molecules H22O O (1 mole H(1 mole H22O)O) = =► (6.022 x 10(6.022 x 102323))

►1.661 x 101.661 x 10-15-15 moles H moles H22OO, bet you , bet you thought it would be a big number, thought it would be a big number, didn’t you?didn’t you?