Chapter 7 WS #1
Name: ________________________________
Ch. 7-1 pg. 228 pp#1-3 Moles ↔ Particles
1. How many ions in 0.187 mol of Na+ ions? Ans.: 1.13 x1023 ions Na1+
2. How many atoms in 1.45x10-17 mol of arsenic? Ans.: 8.73 x106 atoms As
Ch. 7-1 pg. 229
3. How many moles do 5.66x1025 lithium ions, Li+ equal? Ans.: 94.0 mol Li+
4. How many moles in 3.161x1021 molec. of CO2? Ans.: 0.00525 mol CO2
Ch. 7-1 pg. 231 pp#1-3 Mass ↔ Particles
5. What is the mass of 2.11x1024 atoms of copper? Ans.: 223 g Cu
6. What is the mass of 3.01x1023 formula units of NaCl? Ans.: 29.2 g NaCl
Ch. 7-1 pg. 232 pp#1-3
7. Find the number of atoms in 237g Cu. Ans.: 2.25 x1024 atoms Cu
8. Find the number of ions in 20.0g Ca2+. Ans.: 3.00x1023 ions Ca2+
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USE THSE TABLES TO HELP
YOU COMPLETE THE
CHAPTER 5.3 WORKSHEETS
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Chapter 7 WS #2
Name :________________________________
Ch. 7-2 pg. 236 pp#1-2: Average Atomic Mass
1. Find avg at mass Ga if 60.00% has mass 68.926 amu & 40.00% a mass of 70.925 amu. Ans.: = 69.73 amu
2. Do O2 if 99.76% is 15.99 amu, 0.038% mass 17.00 amu, & 0.20% mass of 18.00 amu. Ans.: = 15.99
44amu
Ch. 7.2 p. 253,
42. Find avg at mass Ag if 51.35% is 106.9050 amu and the rest is 108.9045 amu. Ans. = 107.88 amu.
44 Find avg at mass Fe if 5.90% is 53.94 amu, 91.72% is 55.93 amu, 2.10% is 56.94 amu and 0.280% is 57.93
amu. Ans. = 55.84 amu
CH. 7-2 pg. 239 pp#1 Molar Mass
Find the molar mass for each of the following compounds:
CsI _______g/mol
C12H22O11 _______g/mol
I2 _______g/mol
Mg3(PO4)2 _______g/mol
CH. 7-2 pg. 239 pp#2
Write the formula and then find the molar mass for the following
cerium hexaboride CeB6, _______g/mol
aluminum sulfate _______, 342.17 g/mol
iron (III) hydroxide _______, _______ g/mol
tin(II) chloride _______, _______g/mol
tetraphosphorus decoxide _______, _______
g/mol
Ch. 7-2 SR pg. 240 pp#11
Determine the formula, the molar mass, and the number of moles in 2.11g of each of the following compounds.
a. strontium sulfide – Ans.: SrS, _________ g/mol, _________ mol SrS (try to get 1.76x10-2)
b. phosphorus trifluoride – Ans.: _________, _________ g/mol, _________ mol PF3 (2.40 x10-2)
c. zinc acetate – Ans.: _________, _________ g/mol, _________mol Zn(C2H3O2)2 (1.15x10-2)
Chapter 7 WS #3
Name :________________________________
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Ch. 7-3 p. 253 Empirical formulas and percent composition
49. A silver compound is 63.50% Ag, 8.25% N and 28.25% O. Find its empirical formula (ans. AgNO3)
50. A phosphorous oxide is 56.24% P and the rest is oxygen. Find the empirical formula (ans. P2O3)
51. The empirical formula of altretamine is C3H6N2. Molar mass is 210 g/mol. What is its molecular formula?
Ch. 7-3 pg. 248 pp #4: Calculate the percent composition of each of the following:
SrBr2 – Ans.: 35.41% Sr, 64.59% Br
CaSO4 – Ans.: 29.44% Ca, 23.55% S, 47.0% O
Mg(CN)2 – Ans.: 31.83% Mg, 31.46% C, 36.70% N
Ch. 7-3 pg. 248 pp#2 Calculate the % of both elements in sulfur dioxide. Ans.: 50.05% S, 49.95% O
Ch. 7-3 pg. 248 pp#3 Calc. the % comp. of ammonium nitrate. Ans.: 35.00% N, 5.05% H, 59.96% O
Chapter 7: Review Graded Assign. Name:________________________________________ Period:_____ 1 mol of any substance equals _____________________ particles. The base unit for 1 mole is _____ / _____ Which will have the greater number of ions, 1 mol of Cu3(PO4)2 or 1 mol of Si3 N4?_________________________________________ As the atomic mass of elements increases going down the p eriodic table, what happens to the number of atoms in 1 mole of the element? _____________________________________________________________________________________________ Use your periodic table to find the molar mass of Au: _________ Te: _________ V: _________ Be: _________ What element has a molar mass of 10.81 g/mol? _________, 30.97 g/mol _________, and 92.91 g/mol _________ The molar mass of an element = the mass of _______ mole(s) The molar mass of an element is _______________________ to its atomic weight In the chemical formula C2H6, the subscripts indicates there are _____ atoms of C and _____ atoms of H in the compound Determine the molar mass for the following: Al2S3 Mg3 (PO4)2 Potassium Dichromate Calculate the following (Use bar = bar): 1 atom of Ca = _________________ grams 5.67 grams of Ga = _________________ moles 23 moles of C2H6 = _________________ grams 453 grams of Pb(NO3 )2 = _________________ molec. 234 atoms of As = _________________ moles 5.678 moles of C2H4O2 = _________________ molec. The p ercent of O in Fe(OH)3 = _________________ The p ercent composition of K2Cr2O7 = ______________________