Embed Size (px)
DESCRIPTION
HW3. 58. What is the density of each of these gases at STP?. C 3 H 8 Ne NO 2. 58. What is the density of each of these gases at STP?. C 3 H 8 molar mass = 44 g Nemolar mass = 20.2 NO 2 molar mass = 46 g Molar volume is 22.4 L. 58. What is the density of each of these gases at STP?. - PowerPoint PPT Presentation
Citation preview
HW3
58. What is the density of each of these gases at STP?
A. C3H8
B. NeC. NO2
58. What is the density of each of these gases at STP?
A. C3H8 molar mass = 44 g
B. Ne molar mass = 20.2C. NO2 molar mass = 46 g
Molar volume is 22.4 L
58. What is the density of each of these gases at STP?
A. C3H8 44g / 22.4L= 1.96 g/L
B. Ne 20.2g / 22.4L= .90 g/LC. NO2 46g / 22.4L= 2.05 g/L
60. Calculate the percent composition of each compound
A. H2S
B. (NH4)2C2O4
C. Mg(OH)2
D. Na3PO4
60. Calculate the percent composition of each compound
A. H2S
Molar mass is 34gPercent composition of an element is mass of
that element divided by the molar mass of the compound X 100
% H is 2/34 X 100 = 6%% S is 32/34 X 100 = 94%
60. Calculate the percent composition of each compound
B. (NH4)2C2O4
Molar mass = 124g
%N is 28/124 X 100 = 22.6%%H is 8/124 X 100 = 6.5%% C is 24/124 X 100 = 19.3%% O is 64/124 X 100 = 51.6%
60. Calculate the percent composition of each compound
C. Mg(OH)2
Molar mass = 58.3g
%Mg is 24/58 X 100 = 41%%O is 32/58 X 100 = 55%%H is 2/58 X 100 =4%
60. Calculate the percent composition of each compound
D. Na3PO4
Molar mass = 164
% Na is 69/164 X 100 = 42%% P is 31/164 X 100 = 19%% O is 64/164 X 100 = 39%
62. Which of the following compounds has the highest iron content?
A. FeCL2
B. Fe(C2H3O2)3
C. Fe(OH)2
D. FeO
62. Which of the following compounds has the highest iron content?
A. FeCL2
B. Fe(C2H3O2)3
C. Fe(OH)2
D. FeO
What are the molar masses?What are the percent compositions of Fe in each?
62. Which of the following compounds has the highest iron content?
A. FeCL2
Molar mass = 127g%Fe + 56/127 X 100 = 44%
62. Which of the following compounds has the highest iron content?
B. Fe(C2H3O2)3
Molar mass = 233g%Fe is 56/233 X 100 = 24%
62. Which of the following compounds has the highest iron content?
C. Fe(OH)2
Molar mass = 90g%Fe is 56/90 X 100 = 62%
62. Which of the following compounds has the highest iron content?
D. FeOMolar mass = 72g%Fe is 56/72 X 100 = 78%
64. Classify each formula as an empirical or a molecular formula
A. S2Cl2
B. C6H10O4
C. Na2SO3
D. C5H10O5
E. C17H19NO3
F. (NH4)2CO3
64. Classify each formula as an empirical or a molecular formula
A. S2Cl2 M
B. C6H10O4 M
C. Na2SO3 E
D. C5H10O5 M
E. C17H19NO3 E
F. (NH4)2CO3 E
66. Determine the molecular formula for each compound
A. 94.1% O ; 5.9% H; molar mass = 34gB. 40.0% C ; 6.6% H; 53.4% O; molar mass = 120g
66. Determine the molecular formula for each compound
A. 94.1% O ; 5.9% H; molar mass = 34g
.94 X 34g = 32 g O
.059 X 34g = 2 g H
There are two moles of both H and O, so the molecular formula must be H2O2
66. Determine the molecular formula for each compound
B. 40.0% C ; 6.6% H; 53.4% O; molar mass = 120g
.4 X 120 = 48 g C
.066 X 120 = 7.92 g H
.534 X 120 = 64 g O
There are 4 moles of C, 8 moles of H, and 4 moles of O, so the formula must be C4H8O4
