Jeopardy

Review Unit 3 Final Jeopardy Counting Particles Chemical Rxns Stoichiometry Mole Stuff Avogadro & His Number PLUS MORE!

Mole Stuff 100 What is a mole?

Mole Stuff Answer A volumetric unit of measure. One mole has as many particles in it as Avogadro’s number.

Mole Stuff 200 What is the molar mass? How do you find it?

Mole Stuff Answer The molar mass is the mass of one mole of substance. It can be found by reading the atomic masses on the periodic table.

Mole Stuff 300 What is relative mass? How is it connected to the Periodic Table?

Mole Stuff Answer Relative masses are masses relative to the smallest mass available. The atomic masses on the Periodic Table are all relative to Hydrogen.

Mole Stuff 400 What is the molar mass of potassium oxide?

Mole Stuff Answer K 2 O 39 g/mol + 39 g/mol + 16 g/mol 94 g/mol

Mole Stuff 500 How many moles are in a 12.0 g sample of iron (III) oxide?

Mole Stuff Answer moles Fe 2 O 3 Molar mass Fe 2 O 3 : g/mol (12g) * (1mol/159.6g) = mol

Mole Stuff 600 What is the mass of moles of calcium hydroxide?

Mole Stuff Answer 1.11 grams Ca(OH) 2 Molar Mass Ca(OH) 2 : 74 g/mol (0.015mol) * (74g/1mol) = 1.11 g

Avogadro & His Number 100 What is Avogadro’s Number? What does it mean?

Avogadro & His Number Answer 6.02 x This is how many particles are in one mole of substance

Avogadro & His Number 200 How many silver atoms are contained in grams of silver?

Avogadro & His Number Answer 3.63 x atoms (0.65g) * (1mol/107.9g) * (6.02x10 23 part/1mol) = 3.63 * particles

Avogadro & His Number 300 How many atoms are in gram of iron?

Avogadro & His Number Answer 4.86 x atoms Fe

Avogadro & His Number 400 How many molecules are in 13.2 grams of carbon dioxide?

Avogadro & His Number Answer 1.81 x molecules CO 2

Avogadro & His Number 500 How many H 2 molecules are there in 0.25 moles of H 2 ?

Avogadro & His Number Answer 1.5 x particles H 2

Avogadro & His Number 600 How many O atoms in moles of AgNO 3 ?

Avogadro & His Number Answer 8.24 x O atoms

Counting Particles 100 How many oxygen atoms are represented by the formula Pb(C 2 O 4 ) 2 ?

Counting Particles Answer 8

Counting Particles 200 What is total number of atoms represented by the formula Fe 2 (SO 4 ) 3 ?

Counting Particles Answer 17

Counting Particles 300 A 9.56 g sample of copper (II) sulfide is found to contain 6.35 g of copper. What is the percent by mass of the copper and sulfur in this compound?

Counting Particles Answer 66.4% Cuand33.6% S (6.35gCu/9.65g)*100% = 66.4% (3.21gS/9.65g)*100% = 33.6%

Counting Particles 400 Given the diagram of the molecule below, write the empirical and molecular formulas. Label each.

Counting Particles Answer Molecular: C 2 H 6 Empirical: CH 3

Counting Particles 500 When g of phosphorus burns in air, it forms g of phosphorus oxide. Determine the empirical formula of phosphorus oxide.

Counting Particles Answer P 2 O 5 Convert mass to molesRatio of Moles Whole # (0.062g P)*(1mol P/31g P) = 0.002mol P 1x2 = 2 (0.08g O)*(1mol O/16g O) = 0.005mol O 2.5x2 = 5

Counting Particles 600 What is the molecular formula of each compound? Empirical FormulaActual Molar Mass of Compound CH78 g/mole NO292 g/mole

Counting Particles Answer C6H6N2O4C6H6N2O4

Chemical Rxns 100 Balance the following reaction: __Sr(OH) 2 + __FeCl 3  __SrCl 2 + __Fe(OH) 3

Chemical Rxns Answer 3 Sr(OH) FeCl 3  3 SrCl Fe(OH) 3

Chemical Rxns 200 What type of reaction is the following? C 2 H 4 + 3O 2 –> 2CO 2 + 2H 2 O

Chemical Rxns Answers COMBUSTION REACTION boom!

Chemical Rxns 300 A reaction takes place in a test tube. You feel the bottom of the tube and it feels warm. Is the reaction exothermic or endothermic? WHY?

Chemical Rxns Answer EXOTHERMIC The system is releasing heat to the surroundings – energy is exiting the system and moving into your hand.

Chemical Rxns 400 Write a balanced chemical reaction for the reaction below: Magnesium hydroxide reacts with nitric acid (HNO 3 ) to form water and magnesium nitrate.

Chemical Rxns Answer Mg(OH) HNO 3  2 H 2 O + Mg(NO 3 ) 2

Chemical Rxns 500 What is the formula of the missing product molecule? A A

Chemical Rxns Answer A 2 BCD

Chemical Rxns 600 Write a balanced chemical reaction for the following reaction: The combustion of ethane gas, C 2 H 6, produces carbon dioxide gas and water vapor. This reaction is exothermic.

Chemical Rxns Answer 2 C 2 H O 2  4 CO H 2 O

Stoichiometry 100 What do the coefficients in a chemical reaction mean?

Stoichiometry Answer The coefficients tell us how many of each molecular are involved in the reaction. They also tell us the ratio (in moles) of each compound to the others.

Stoichiometry 200 Hydrogen sulfide (H 2 S) burns in air to produce sulfur dioxide and water. How many moles of oxygen gas would be needed to completely burn 8 moles of hydrogen sulfide?

Stoichiometry Answer 12 mol O 2 Equation: 2H 2 S + 3O 2  2SO 2 + 2H 2 O Before: 8 mol xs 0 mol 0 mol Change: -8 mol x(3/2) 12 mol +8 mol +8 mol After: 0 mol xs8 mol 8 mol

Stoichiometry 300 What is the ratio of moles of oxygen gas to moles of carbon dioxide in the reaction below? 2C 2 H 6 + 7O 2  4CO 2 + 6H 2 O

Stoichiometry Answer 7 to 4 7:4 7/4

Stoichiometry 400 Can you use grams when filling out a BCA table? Why or Why not???

Stoichiometry Answer No grams allowed! Only moles. The ratios in a chemical reaction only apply for moles of each substance.

Stoichiometry 500 Calculate the number of moles of sodium oxide that should be produced when 6.50 grams of sodium react with oxygen gas.

Stoichiometry Answer 0.14 mol Na 2 O (6.5g Na)*(1mol/23g Na) = 0.28 mol Na Equation: 4Na + O 2  2Na 2 O Before: 0.28mol xs 0 mol Change: -.28mol -.07mol +0.14mol After: 0 mol xs 0.14 mol

Stoichiometry 600 What does stoichimetry help us do?

Stoichiometry Answer ……… Use ratios to determine the amounts of substances that are used up, formed, or produced within a chemical reation.

Final Jeopardy

Final Jeopardy - Answer