Review Game MOLES MOLES MOLES

What is the percent of Silver in Silver (I) Nitrate? Percent Composition What is the percent of Silver in Silver (I) Nitrate? AgNO3 = 108 + 14 + 16(3) = 170 % Ag = 108/170 x 100 = 63.5% 63.5 % 2. 43.4 % 3. H 6.7% C 40% O 53.3% 4. 25.9 % N 74.1%O 5. Carb 3.2% Nit 1.59 %

What is the percent of Sodium in Sodium Carbonate? Percent Composition What is the percent of Sodium in Sodium Carbonate? Na2CO3 = 2(23) + 12 + 3(16) = 106 % Na = 2(23)/106 x 100 = 43.4 %

What is the percent composition of all elements in HC2H3O2? %H = 4/60 x 100 = 6.67% %C = 2(12)/60 x 100 = 40% %O = 2(16)/60 x 100 = 53.33 %

Percent Composition What is the percent, by weight, of the elements in dinitrogen pentoxide? N2O5 = 2(14) + 5(16) = 108 %N = 28/108 x 100 = 25.9% %O = 80/108 x 100 = 74.1%

Percent Composition Which has a higher percentage of hydrogen, carbonic acid or nitric acid? Carbonic Acid = H2CO3 = 2(1) + 12 + 3(16) = 62 2/62 x 100 = 3.23% Nitric Acid = HNO3 = 1 + 14 + 3(16) = 63 1/63 x 100 = 1.59% ANSWER: CARBONIC ACID

4.56 grams of Zinc (II) Phosphate is equal to how many moles? Mole Conversions 4.56 grams of Zinc (II) Phosphate is equal to how many moles? 4.56 g Zn3(PO4)2 / 385 = 0.0118 moles

29.86 grams of Barium Carbonate is equal to how many moles? Mole Conversions 29.86 grams of Barium Carbonate is equal to how many moles? 29.86 g BaCO3 / 197 = 0.1513 moles

4.96 moles of Potassium Hydroxide is equal to how many grams? Mole Conversions 4.96 moles of Potassium Hydroxide is equal to how many grams? 4.96 moles KOH x 56 = 278 g

0.98 moles of Aluminum Nitrate is equal to how many grams? Mole Conversions 0.98 moles of Aluminum Nitrate is equal to how many grams? 0.98 moles Al(NO3)3 x 213 = 210 g

6.59 x 1023 molecules of CO2 is equal to how many moles? Mole Conversions 6.59 x 1023 molecules of CO2 is equal to how many moles? 6.59 x 1023 molecules / 6.02 x 1023 = 1.09 moles

9.85 x 1023 formula units of KCl is equal to how many moles? Mole Conversions 9.85 x 1023 formula units of KCl is equal to how many moles? 9.85 x 1023 for u / 6.02 x 1023 = 1.64 moles

0.23 moles of calcium is equal to how many atoms? Mole Conversions 0.23 moles of calcium is equal to how many atoms? 0.23 moles Ca x 6.02 x 1023 = 1.4 x 1023 atoms

1.25 moles of Cadmium Chloride is equal to how many formula units? Mole Conversions 1.25 moles of Cadmium Chloride is equal to how many formula units? 1.25 moles CdCl2 x 6.02 x 1023 = 7.53 x 1023 for u

56.8 L of nitrogen gas is equal to how many moles at STP? Mole Conversions 56.8 L of nitrogen gas is equal to how many moles at STP? 56.8 L N2 / 22.4 = 2.54 moles

25.9 L of oxygen gas is equal to how many moles at STP? Mole Conversions 25.9 L of oxygen gas is equal to how many moles at STP? 25.9 L O2 / 22.4 = 1.16 moles

1.96 x 1023 molecules of CO2 is equal to how many liters at STP? Mole Conversions 1.96 x 1023 molecules of CO2 is equal to how many liters at STP? 1.96 x 1023 molecules CO2 / 6.02 x 1023 x 22.4 = 7.29 L

What is the volume of 0.75 moles of He at STP? Mole Conversions What is the volume of 0.75 moles of He at STP? 0.75 moles He x 22.4 = 17L

What is the mass of 1.02 x 1023 molecules of xenon trichloride? Mole Conversions What is the mass of 1.02 x 1023 molecules of xenon trichloride? 1.02 x 1023 molecules XeCl3 / 6.02 x 1023 x 236 = 39.9g

What is the volume of 2.56 grams of chlorine gas at STP? Mole Conversions What is the volume of 2.56 grams of chlorine gas at STP? 2.56 g Cl2 / 71 x 22.4 = 0.809 L

How many formula units are present in 5.8 grams of Calcium hydroxide? Mole Conversions How many formula units are present in 5.8 grams of Calcium hydroxide? 5.8 g Ca(OH)2 / 74 x 6.02 x 1023 = 4.7 x 1022 for u

What is the mass of 58.3 L of Argon gas, at STP? Mole Conversions What is the mass of 58.3 L of Argon gas, at STP? 58.3 L Ar / 22.4 x 40 = 104 g

Empirical and Molecular Formulas A compound is 85.7% C and 14.3 % H. Determine the molecular formula if the molar mass is 70 g/mol. 85.7 g C / 12 = 7.14167 / 7.14167 = 1 14.3 g H / 1 = 14.3 / 7.14167 = 2 Empirical Formula = CH2 = 14 70/14 = 5 Molecular Formula = C5H10 1. C3H4O3 C6H8O6 2. CH2 C5H10 3. C4H9 C8H18

Empirical and Molecular Formulas A compound is 41% C, 4.5 % H, and 54.5% O. Calculate the molecular formula if the molar mass is 176 g/mol. 41 g C / 12 = 3.4167 / 3.40625 = 1 x 3 = 3 4.5 g H / 1 = 4.5 / 3.40625 = 1.33 = 4/3 x 3 = 4 54.5 g O / 16 = 3.40625 / 3.40625 = 1 x 3 = 3 Empirical Formula C3H4O3 = 88 176/88 = 2 Molecular Formula C6H8O6 1. C3H4O3 C6H8O6 2. CH2 C5H10 3. C4H9 C8H18

Empirical and Molecular Formulas Octane contains 84.089% C and 15.911% H and has a molar mass of 114.26 g/mol. Determine the empirical and molecular formulas. 84.089 g C / 12 = 7.0074 / 7.0074 = 1 x 4 = 4 15.911 g H / 1 = 15.911 / 7.0074 = 2.25 = 9/4 x 4 = 9 Empirical Formula = C4H9 = 57 114.26 / 57 = 2 C8H18 1. C3H4O3 C6H8O6 2. CH2 C5H10 3. C4H9 C8H18

Calculate the percent of water in sodium sulfate decahydrate Hydrates Calculate the percent of water in sodium sulfate decahydrate Na2SO4 . 10H2O = 2(23) + 1(32) + 4(16) + 10(18) = 322 % H2O = 18(10)/322 x 100 = 55.9% 1. 55.9 % 2. 6H2O 45.7 % 3. 3H2O 14.2 %

Hydrates A 1.62 gram sample of CoCl2 hydrate was heated. The anhydrous salt has a mass of 0.88g. Calculate the percent water and the formula of the hydrate. Mass water = 1.62 – 0.88 = 0.74 g 0.88 g CoCl2 / 130 = 0.006769 / 0.006769 = 1 0.74 g H2O / 18 = 0.04111 / 0.006769 = 6 CoCl2 . 6H2O % water = mass water / mass hydrate x 100 = 0.74 / 1.62 x 100 = 46 % 1. 55.9 % 2. 6H2O 45.7 % 3. 3H2O 14.2 %

Hydrates A 1.21 g Pb (C2H3O2) 2 hydrate was heated. The salt left over had a mass of 1.04g. Calculate the percent water and the formula of the hydrate. Mass water = 1.21 – 1.04 = 0.17g 1.04 g Pb(C2H3O2)2 / 325 = 0.0032/ 0.0032 = 1 0.17 g H2O / 18 = 0.009444 / 0.0032 = 3 Pb(C2H3O2)2 . 3H2O % Water = 0.17 / 1.21 x 100 = 14.1 % 1. 55.9 % 2. 6H2O 45.7 % 3. 3H2O 14.2 %

I have 450 grams of hydronitric acid. How many atoms are present? More Problems I have 450 grams of hydronitric acid. How many atoms are present? 450 g H3N / 17 x 6.02 x 1023 x 4 = 6.4 x 1025 atoms

More problems If a sample of dinitrogen pentoxide has 4.5 x 1024 atoms, how many liters are present? 4.5 x 1024 atoms N2O5 x (1 molecule/7 atoms) x (1 mol/6.02 x1023 molecules) x 22.4 = 24 L

Hydrate I have 40 grams of a sodium phosphate hydrate. It loses 46.8% of its mass upon heating. What is the formula of the hydrate? 0.468 x 40 = 18.72 grams water 40 – 18.72 = 21.28 grams anhydrous 18.72g H2O/18 = 1.04/.129756 = 8 21.28g Na3PO4 / 164 = .129756/.129756 = 1 Na3PO4 . 8H2O

Hydrate The percent water in a 20.0 gram sample of potassium nitrate hydrate is 41.6%. What is the formula of the hydrate? .416 x 20 = 8.32 grams H2O / 18 = .462222/0.11564 = 4 20 – 8.32 = 11.68 grams KNO3/101 = 0.11564/.11564 = 1 KNO3.4H2O

Hydrate When 14.7 grams of a titanium (IV) nitrate hydrate is heated, 1.59 grams of mass is lost. What is the percent water, formula and name of hydrate? 14.7 – 1.59 = 13.11 grams 13.11 grams Ti(NO3)4 / 296 = 0.04429/0.004429 = 1 1.59 grams H2O / 18 = 0.08833/0.004429 = 2 Ti(NO3)4 . 2H2O Titanium (IV) nitrate dihydrate % water = 1.59/14.7 x 100 = 10.8 %