Chemistry Day 48. Thursday, January 24 th Monday, January 28 th, 2019

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1 Chemistry Day 48 Thursday, January 24 th Monday, January 28 th, 2019

2 Do-Now: S2 Brainstorm! 1. Write down today s FLT 2. What are the units of molar mass? 3. Use your periodic table to calculate the molar mass of NaOH. Show all work. 4. How many moles is 5.69 g of NaOH? Show all work and units. Check sig figs. 5. Number your paper for your brainstorm. Take out your planner and ToC

3 FLT I will be able to determine the volume of a given quantity of gas at STP by completing Molar Volume CN Standard HS-PS1-7: Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction

4 Chemical Quantities

5 Recall

6 Moles ßà Molecules x molecules 1 mole 1 mole x molecules

7 Moles ßàMass 1 mol Na g Na g Na 1 mol Na

8 Mole Volume Relationship

9 Mole-Volume Relationship What are the units for volume? Liters!

10 Mole-Volume Relationship Many of the chemicals we deal with are in the physical state as GASES They are difficult to mass Consequently, we often use VOLUME for gases

11 Mole-Volume Relationship Volume may be affected by (1) Temperature (2) Pressure Consequently, we need to compare gases at a constant temperature and pressure for consistency

12 Mole-Volume Relationship Standard Temperature and Pressure (STP): 1 atm of pressure and 273 K (0 C)

13 Mole-Volume Relationship Molar Volume: At STP, 1 mole of any gas occupies a volume of 22.4 L

14 Sample Problems

15 Example 1 What is the volume of 4.59 mole of CO 2 gas at STP?

16 Example 2 How many moles is 5.67 L of O 2 at STP?

17 Recall Density = mass/volume (g/l)

18 Example 3 The density of a gas is g/l at STP. What is the molar mass of the gas?

19 Example 4 The density of a gas is 3.58 g/l at STP. What is the molar mass of the gas?

20 Chemistry Day 49 Tuesday, January 29 th Wednesday, January 30 th, 2019

21 Do-Now: Percent Composition CN 1. Write down today s FLT 2. Write the conversion factor for converting from moles to molecules. 3. Write the conversion factor for converting from Liters to moles at STP. 4. You have grams of NO 2. Convert this to moles of NO 2. Show all work. 5. Now, convert this to molecules of NO 2. Show all work. Take out your planner and ToC

22 FLT I will be able to calculate the percent composition by mass of an element in a compound by completing Percent Composition CN Standard HS-PS1-7: Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction

23 Chemical Quantities

24 Recall

25 What are Representative Particles? We can use Avogadro s number to convert the representative particle to moles Ask yourself is the representative particle a MOLECULE/FORMULA or is it an ATOM? Ex/ 1. NaCl 2. Pb 3. N 2

26 Atoms vs. Molecules How many atoms are in the following? CaCO 3 Al 2 (SO 4 ) 3 5 atoms = 17 atoms How many ions in the following? CaCl 2 NaOH Al 2 (SO 4 ) 3 3 total ions (1 Ca 2+ ion and 2 Cl 1- ions) 2 total ions (1 Na 1+ ion and 1 OH 1- ion) 5 total ions (2 Al SO 4 2- ions)

27 Converting to Atoms Example How many molecules of CO 2 are in 4.56 moles of CO 2 versus how many ATOMS are in 4.56 moles of CO 2?

28 Multi-Step Conversions

29 Multi-Step Conversions Conversions involving more than one step must be calculated together This avoids rounding errors Ex/ Convert 2.5 x atoms of Au to grams.

30 Percent Composition and Chemical Formulas

31 Calculating % Composition Like all percent problems: part total x 100 % = percent 1) List the masses of each element and total mass (use given #s OR your PT) 2) Divide each element s mass by the total mass and x 100% (inc. units)

32 Example Calculate the percent composition of a compound that is made of 29.0 grams of Ag with 4.30 grams of S.

33 Example 2 Calculate the percent composition of C 2 H 4

34 Try This: Calculate the percent composition of H 2 O

35 Chemistry Day 50 Thursday, January 31 st Friday, February 1 st, 2019

36 Do-Now: Lab Day Do-Now Turn in your Chemical Quantities Packet. No working on the packet. 1. Write down today s FLT Copy and complete each: 2. Avogadro s number is, and, when looking at fluorine, it can help me convert from to. 3. The number of atoms in C 6 H 12 O 6 is and the number of ions in NH 4 NO 3 is. 4. The units of molar mass are /. 5. From moles, I can convert to,, or (at STP). Take out your planner and ToC

37 FLT I will be able to perform calculations involving mass, moles, particles and percent composition by completing Mole Lab Standard HS-PS1-7: Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction

Chemistry Tuesday, February 14 Wednesday, February 15, 2017

Chemistry Tuesday, February 14 Wednesday, February 15, 2017 Do-Now: BrainPOP: Moles 1. Write down today s FLT 2. What are the units of molar mass? 3. Use your periodic table to find the molar mass of NaOH.