Chapter 10 Chemical Quantities

A representative particle (RP) refers to the species present in a substance, usually atoms(S), molecules(SO 2 ), or formula units(NaCL)

A representative particle (RP) refers to the species present in a substance, usually Element: atoms, Covalent Bond: molecules, or Ionic Bond: formula units

A representative particle (RP) is: 1 atom, 1 molecule, or 1 formula unit.

3 Word Summary: Representative Particle = Atoms, Molecules or Ionic Formula.

How many atoms do you see? Molecules?

You must state very specifically what the particle represents: atoms or molecules and of what? State what is the RP: An atom of O, An atom of C or a molecule of CO 2 ?

Does this look like air? Does air have a representative particle?

Answer is NO! There is not a particle of air. Air is about 80% N 2 and 20% O 2. Air is composed of several representative particles mixed together. So Mixtures do NOT have representative particles.

The mole = mol 6.02 x representative particles (RP) of a substance is called Avogadro's number.

MEMORIZE: Mole = 6.02 x 10 23

Emphasis is on Why on the 23 and not the 6.02? 1.) If you have $5 x /- $1 Does the 1 matter? 2.) If you have $5 x / Does it matter? Which is more important?

1.) If you have $5 x /- $1 Does the 1 matter? This ranges from 400,000 to 600,000 2.) If you have $5 x / Does the 1 matter? This ranges from $50,000 to $5 million. Which is more important? 1.) 400,000 to 600,000 or 2.) $50,000 to $5 million

A mole is just a name of a number. Like Pi = and e = Mole = 6.02 x 10 23

A mole is just a name of a number. Like Thousands, Millions, Billions, Trillions, Quadrillions, Gazillionbillions Mole = 6.02 x 10 23

There is a very specific reason that we use a mole, Atomic Mass in grams is equal to 1 mole of an element. Do some examples Have students do elements off the periodic table. Shoe 1 mole samples on counter.. Molar Mass = grams of 1 mole of atoms = Atomic Mass 6.02 x 10 23

Avogadro discovered the mole, but the exact number was determine later. So it was named after. So it’s 2 nd name is Avogadro's number 6.02 x 10 23

Review Dimensional Analysis. Known x Conversion Factor = Wanted Known x Wanted = Wanted Known Example, convert feet to inches. 4 ft x 12 inches = 48 inches 1 ft. 1.) Do the dimensions or units first. Cross off feet and inches are left. 2.) Fill in # and multiply and divide the numbers.

How many atoms of sodium are in 2.0 moles? Na = RPmoles

How many atoms of sodium are in 2.0 moles? Na = RPmole

How many atoms of sodium are in 2.0 moles? Na = RP Note: Adjust answer for 1.) Scientific Notation 2.) Significant Figuresmole

How many carbon atoms are in 3.0 moles of C 2 S? 1 molecule C 2 S = 1 RP

How many carbon atoms are in 3.0 moles of C 2 S? 1 molecule C 2 S = 1 RP 1 RP has 2 C atoms 3 mol of C 2 S x 2 C atoms = 6 mol C = 6 mol C x 6.0 x atoms/mol = 36 x atoms = 3.6 x atoms

How many grams of carbon are in 3.0 moles of C 2 S?

How many grams of carbon are in 3.0 moles of C 2 S? 3.0 mol C 2 S = 6.0 mol C = 6.0 mol C x 12 g/mol C = 72g C

How many pennies is 1 mole of pennies? Would it cover the earth? How deep?

How much is a mole of pennies? A mole of pennies would cover the entire Earth to a depth of 300 m, or 3 football fields (With end zones).

Molar Road Map: Conversion Factors for moles. Pg 323 # of Atoms = moles x 6.0 x atoms/mol Mass (g) = moles x atomic mass (from periodic table) Volume of Gas = (at STP) moles x 22.4 L / mol STP = Standard Temperature and Pressure = 0° C, kPa = 1 atmospheric pressure at sea level on a freezing day.

Nest section uses: Molar Road Equations # of Atoms = moles x 6.0 x atoms/mol Mass (g) = moles x atomic mass (from periodic table)

How many hydrogen atoms are in 1.5 moles of hydrogen?

How many hydrogen atoms are in 1.5 moles of hydrogen? 1 atom H = 1 RP 1 RP has 1 H atom 1.5 mol of H x 1 H atom = 1.5 mol H 1.5 mol H x 6.0 x atoms/mol = 9.0 x atoms Always ask, is Sci Not and Sig Figs correct?

How many hydrogen atoms are in 1.5 moles of hydrogen? Part 2: What is their mass?

1 atom H = 1 RP 1 RP has 1 H atom 1.5 mol of H x 1 H atom = 1.5 mol H Mass = moles x atomic mass 1.5 mol H x 1.0 g/mol = 1.5 g H

How many hydrogen atoms are in 1.5 moles of water?

How many hydrogen atoms are in 1.5 moles of water? 1 molecule H 2 O = 1 RP 1 RP has 2 H atoms 1.5 mol of H 2 O x 2 H atom / mol = 3.0 mol H 3.0 mol H x 6.02 x atoms/mol = x atoms = 1.8 x atoms

How many grams of hydrogen are in 1.5 moles of water?

How many grams of hydrogen are in 1.5 moles of water? 1 molecule H 2 O = 1 RP 1 RP has 2 H atoms 1.5 mol of H 2 O x 2 H atom / mol = 3.0 mol H Mass = moles x atomic mass 3.0 mol H x 1.0 g/mol = 3.0 g H

How many moles of carbon are in 1.0 mole of C 2 S dicarbon monosulfide? A) 1 mole B)2 moles C) 3 moles D) 4 moles

How many moles of carbon are in 1.0 mole of C 2 S dicarbon monosulfide? A) 1 mole B)2 moles C) 3 moles D) 4 moles

What is the molar mass of 1 mol of calcium? 1 mole of any element is that compounds atomic mass expressed in grams

What is the molar mass of 1 mol of calcium? 1 mole of any element is that compounds atomic mass expressed in grams 1 mole Ca = 40.8 g / mol Because atomic mass is 40.8 amu

What is the molar mass of calcium hydroxide?

What is the molar mass of calcium hydroxide? Ca(OH) 2 List each atom and it’s quantity. Multiply by it’s atomic mass add. Ca x 1 O x 2 H x 2 40 x 1 16 x 2 1 x 2 40 x x x 2 = = 74g

Common Atomic Masses H 1 C 12 N 14 O 16 Ne 20 Fe 56 U 238

What is the molar mass of the following? Neon Dinitrogen monoxide Calcium chloride

Ne = 20g N 2 O=44g CaCl 2 = 110g

What is the molar mass of Mg(C 2 H 3 O 2 ) 2 ?

What is the molar mass of Mg(C 2 H 3 O 2 ) 2 ? 142g

How many moles are in 55g of carbon? How many grams are in 22 moles of CO 2 ? How many moles in 55g Ne? How many moles in 55g oxygen? How many C atoms in 55g C 4 H 10 ? How many H atoms in 155g HC 2 H 3 O 2 ? Answers on Following Slides

How many moles are in 55g of carbon?

How many grams are in 22 moles of CO 2 ?

How many moles in 55g Ne?

How many moles in 55g oxygen?

How many C atoms in 55g C 4 H 10 ?

How many H atoms in 155g HC 2 H 3 O 2 ?

GAS VOLUME 1 mole of any gas at STP is 22.4L

MEMORIZE 1 mole of any gas at STP is 22.4L Remember this WOD? Volume of Gas = (at STP) moles x 22.4 L / mol STP = Standard Temperature and Pressure = 0° C, kPa See mole box on page 301. What does STP stand for?

1 mole of any gas at STP is 22.4L. What does STP stand for? Standard temperature and pressure 0 o C and 1 atm Where is it 1 atm? Why pick 0 o C?

1 mole of any gas at STP is 22.4L. What does STP stand for? Standard temperature and pressure 0 o C and 1 atm Where is it 1 atm? ANS: Sea Level Why pick 0 o C? ANS: Freezing temp is easy to recreate.

How many atoms are in 44.8L of oxygen?

How many C atoms are in 2.2L of C 3 H 8(g) ? (g) at the end means it is a gas.

How many L are in 3.4 x CO 2 molecules?

How many carbon monoxide moles are in 44.8L of CO? A)1 mol B)2 mol C)1.00 mol D)2.00 mol

Similar Test Question One drop of H 2 O has a mass of 0.1g. How many atoms of hydrogen are contained in a single drop of water?

Start 10.3 Percent composition

Percent composition = % of elements that make a compound mass (element) ÷ mass (compound) x 100% = Percent is about mass, not volume, not moles, not atoms or molecules.

What is the percent composition of H 2 O? Use molar masses. mass (element) ÷ mass (compound) x 100% = » % Composition Hydrogen H / Total x 100% 2g/18g x 100% = 11.1% Hydrogen Oxygen O / Total x 100% 16g/18g x 100% = 88.9% Oxygen Total = 100% (or close because of rounding) 11.1% H and 88.9% Oxygen = 100%

What is the percent composition of carbon tetrafluoride?

Which has a higher percentage of carbon CO or C 3 H 8 OH?

Element Mass = Percent composition x Total Mass

A 175g sample of CO 2 contains how many g of carbon?

Similar Test Question How many grams of sodium can be obtained from 42.5g of sodium nitrate?

Empirical formula = lowest ratio of elements in a compound, same % composition C 2 H 4 C 4 H 8

Which of the following is an example of an empirical formula? A)CO B)C 2 H 2 C)C 2 Cl 4 D) C 2 H 6

Test (like) Question The compound is 5.9% H. What is the molecular formula and empirical formula for this compound if it is only composed of oxygen and hydrogen?

Solution 100% = 100g 5.9%H = 5.9gH 94.1%O = 94.1gO Convert grams to moles 5.9 mol H5.9 mol O Divided by smallest to find EF (emp. Form.) (5.9/5.9) 1mol H 1 mol O 1g + 16g = 17g

Solution Multiply to find MF (molecular formula) OH(17g) x 2 = 34 H 2 O 2

Test (like) question 20.0g of sugar will produce how much carbon? Sugar = C 12 H 22 O 11

Solution Find percent composition of Carbon 144g C / 342g C 12 H 22 O 11 x 100% 42.1% C Find amount of carbon (decimal not %) x 20g = 8.42g C

20.0g powdered sugar (C 12 H 22 O 11 ) to 10 ml 18M sulfuric acid. Carbon and steam (water) will be produced. Add water/sodium bicarbonate to clean. Solid in trash.

Review Molar Mass

Gram atomic mass – atomic mass of 1 mol of an element expressed in grams 1 mol carbon = 12g Gram molecular mass – mass of 1 mol of that compound 1 mole H 2 O = 18g

Gram formula mass – mass of 1 mol of an ionic compound 1 mol of NaCl = 58 g

Molar mass – the mass of 1 mole of any element or compound (add atomic masses) 1 mol of NaCl = 58 g/mol mol carbon = 12g/mol 12 1 mole H 2 O = 18g/mol