Ch 5.11 & Ch 6
Title and Highlight Right Side NOTES ONLY TN Ch 5.11 Topic: EQ: Date Write Question out (left side of red line) and answer it (Highlight answer) based on from what you read. Write out the notes from my website. You may use different color pens. Use Bullets or Number notes. Space out your notes so you can add any additional into during lecture. NO HIGHLIGTING, UNDERLINING, etc WE WILL DO OUR FOCUS NOTES TOGETHER Write 2-3 sentences (end of notes) from what you learned from reading, notes, and/or lecture.
Title and Highlight LEFT Side PICTURES, PRACTICE PROBLEMS, ETC TN Ch 5.11 DRAW ANY PICTURES, FIGURES, AND WRITE OUT ANY PRACTICE PROBLEMS/QUESTIONS. WE WILL ANSWER THEM TOGETHER. LEAVE SPACES SO WE CAN ANSWER QUES.
READ Ch 5.11 (pg. 148-149) Write Questions & Answer Questions #24 (notes side) Highlight answer
For any compound, the formula mass is the sum of the atomic masses of all the atoms in its chemical formula (units = amu atomic mass unit):
Formula Mass Rules What is the formula mass for CaCl 2 Ca 1 x 40.078 amu = 40.078 amu + Cl 2 x 35.453 amu = 70.906 amu = 110.984 amu CaCl 2
Left side Find the formula mass for the following ionic compounds a. MgSO 4 b. KCN c. Ca(OH) 2
6.02 x 10 23 READ Ch 6.1-6.3 (pg. 165-168 stop at converting grams ad moles) Write Questions & Answer Questions #1-4 (notes side) Highlight answer
What is a conversion factor? It relates how an object compares to another. Usually one item is set to equal 1. Examples: 1 min = 60 sec 1 year = 365 days 1 doz eggs= 12 eggs 1 pound = 16 ounces
With atoms, we must use their mass as a way to count them. Atoms - too small & too many to count individually. We need a larger # because atoms are so small. Chemist s use mole (mol).
Avogadro s number = 602 billion trillion 602,000,000,000,000,000,000,000 6.02 X 10 23 (in scientific notation) This number is named in honor of Amedeo Avogadro (1776 1856), 1 mol = 6.02 10 23 items (units change) A large amount!!!!
How big is a mole? (ed.ted.com)
One mole of marbles = 6.02 10 23 marbles. One mole of sand grains = 6.02 10 23 sand grains. The value of the mole is defined as being equal to the number of atoms in exactly 12 g of pure carbon-12. (Very important) This definition of the mole establishes a relationship between mass (grams of carbon) and number of atoms (Avogadro s number).
1 mole of hockey pucks would equal the mass of the moon! (Moon mass 7.3 x 10 22 kg) 1 mole of basketballs would fill a bag the size of the earth!
Enough soft drink cans to cover the surface of the earth to a depth of over 200 miles. If you had Avogadro's number of unpopped popcorn kernels, and spread them across the United States of America, the country would be covered in popcorn to a depth of over 9 miles. If we were able to count atoms at the rate of 10 million per second, it would take about 2 billion years to count the atoms in one mole.
1 mole C 1 mole H 2 O 1 mole NaCl = 6.02 x 10 23 C atoms = 6.02 x 10 23 H 2 O molecules = 6.02 x 10 23 NaCl formula units Representative Particles: Atom = 1 element Formula unit (f.u.) = Ionic Compound Molecule = Molecular Compound Ion = charge atom
Left side How many molecules are in 2.50 moles of C 12 H 22 O 11?
Left side a. Number of atoms in 0.500 mole of Al b.number of moles of S in 1.8 x 10 24 atoms S
6.02 x 10 23 READ Ch 6.3 (pg. 168-170) Write Questions & Answer Questions #5-7 (notes side) Highlight answer
The molar mass of any element the mass of 1 mol of that element. (Cool part is that it s the same calculation as gram formula mass Ch 5.11) Need to see the difference: 1 Cu atom has atomic mass = 63.55 amu. 1 mol of Cu atoms has mass of 63.55 g. Do you see the difference????
Molar Mass - 1 mole equals the sum of the atomic masses in grams ( not amu). Need Periodic Table!!!! Mass (g) molar mass Moles (mol) 1 step conversion!!
Find the molar mass from PT (DON T ROUND!!!) A.1 mole of Br atoms B.1 mole of Sn atoms = 79.904 g = 118.710 g
Left side How many moles of carbon are in 26 g of carbon?
Left side How many grams of Al are in 3.00 moles of Al?
6.02 x 10 23 READ Ch 6.3 (pg. 171-172) No Questions
molar mass 6.02 10 23 MASS IN GRAMS MOLES NUMBER OF PARTICLES Everything must go through Moles!!!
Left side How many atoms of Cu are present in 35.4 g of Cu? Remember 6.02 X 10 23 atoms = 1 mole = molar mass (g)
Left side How many atoms of K are present in 78.4 g of K? Remember 6.02 X 10 23 atoms = 1 mole = molar mass (g)
Left side How many grams of Ca are present in 5.23 x 10 24 atoms Ca? Remember 6.02 X 10 23 atoms = 1 mole = molar mass (g)
6.02 x 10 23 READ Ch 6.4 (pg. 172-174) Write Questions & Answer Questions #8 (notes side) Highlight answer
Molar mass is the mass of 1 mol of molecules (units used for only molecules) or formula units (units used for only ionic compounds) of that compound. Just like Ch 5.11!!! Just different units because of moles 1 mole of CaCl 2 Ca 1 x 40.078 g = 40.078 g + Cl 2 x 35.453 g = 70.906 g = 110.984 g/mol CaCl 2
molar mass 6.02 10 23 MASS IN GRAMS MOLES NUMBER OF PARTICLES (g/mol) (particles/mol) Everything must go through Moles!!!
Left side Find the mass of 2.1 10 24 formula units of NaHCO 3.
Left side Find the formula units of 51.5g of NaHCO 3.
6.02 x 10 23 READ Ch 6.5 (pg. 175-179) Write Questions & Answer Questions #10 (notes side) Highlight answer
The relationships in a chemical formula allow us to convert between moles of the compound and moles of an element (and vice versa).
Left side
Left side Find the moles of sodium in 15 g of NaCl.
3 step conversion Get out conversion chart to add a new box! 6.02 x 10 23
Left side How many grams of O are present in 78.1 g CO 2?
6.02 x 10 23 READ Ch 6.6-6.7 (pg. 180-182) Write Questions & Answer Questions #12 (notes side) Highlight answer
Left side Draw and color
Left side Draw and color
Left side Draw and color
The mass percent composition, or percent composition, of an element is the element s percentage of the total mass of the compound. You use this calculation everyday.called your grades!!!
Step 1: Calculate the molar mass of the compound. Step 2: Divide each elements total mass by the molar mass of the compound. Step 3: Convert the decimal to a % by multiplying by 100. Step 4: Al ways check your work!!!! All element % s should equal 100%.
Left side Find the % composition of each element in Na 3 PO 4
Left side Find the % composition of CARBON in C 4 H 10
6.02 x 10 23 READ Ch 6.8 (pg. 183-185) Write Questions & Answer Questions #13-14 (notes side) Highlight answer
Empirical and Molecular Formulas give the numbers of atoms or moles of each element always in a whole number ratio (the law of definite proportions). 1. Empirical Formula: The formula of a compound with the smallest whole number ratio of the atoms present.
1. Determine the mass in grams of each element present. If % s are given, check to see if % s equal 100%. If yes, then the 100%=100g. So, change % s to grams. 2. Calculate the number of moles of each element. 3. Divide each by the smallest number of moles to obtain the simplest whole number ratio. 4. If whole numbers are not obtained * in step 3, multiply through by the smallest number that will give all whole numbers (**See bottom of page 185 for help with what # to multiply with to get whole subscript number) * Be careful! Do not round off numbers prematurely
Left side A sample of a brown gas, a major air pollutant, is found to contain 2.34 g N and 5.34g O. Determine the empirical formula for this substance.
Left side A substance has the following composition by mass: 60.80 % Na ; 28.60 % B ; 10.60 % H What is the empirical formula of the substance?
6.02 x 10 23 READ Ch 6.8 (pg. 186-187) Write Questions & Answer Questions #15 (notes side) Highlight answer
2. Molecular Formula: The formula that states the actual number of each kind of atom found in one molecule of the compound. (biggest ratio)
1. Need Empirical Formula first (look at rules from Ch 6.8) Solve for it!! 2. Calculate the molar mass of E.F. 3. Book MUST give you the molar mass of Molecular Formula. 4. To find M.F.. molar mass of M.F. = whole number ( E.F. ) = M.F. molar mass of E.F.
Left side A compound has an empirical formula of NO 2. The colorless liquid, used in rocket engines has a molar mass of 92.0 g. What is the molecular formula of this substance?