# Molarity Lab 4/12/11 Let’s make a solution or 2. 1) With a partner, make 20 milliliters of a 2.0 Molar solution of NaCl. 2)Next, make exactly 175 mL of.

## Presentation on theme: "Molarity Lab 4/12/11 Let’s make a solution or 2. 1) With a partner, make 20 milliliters of a 2.0 Molar solution of NaCl. 2)Next, make exactly 175 mL of."— Presentation transcript:

Molarity Lab 4/12/11 Let’s make a solution or 2. 1) With a partner, make 20 milliliters of a 2.0 Molar solution of NaCl. 2)Next, make exactly 175 mL of a 0.147M solution of NaCl. 3) How much solution is created, in a 0.45M solution if we use 25.6 grams of sucrose (in yellow packet) to make the solution. Be sure to record the mass of salt used in each. Make this neat and easy for me to read/grade.

Molarity cont. 4) Dilute the 0.147M solution to a 0.08 M solution. How do you do this? What is new volume? How much water? M 1 V 1 =M 2 V 2 0.147M(.167L) = 0.08M(V2) V 2 = 0.307L Add.140 L of water

Daily EQ:What is stoichiometry? warm-up Mole conversions (Do you remember these?) 1) How many moles are there in 500 grams of O 2 ? 2) At STP, how many moles of O 2 are in 500 L? 3) How many molecules of O 2 are in 25.5 moles of O 2 ? 4) How many atoms are in 25.5 moles of O 2 ?

Stoichiometry Chapter 12 in your book mole ratio- stoichiometry - a conversion factor derived from the coefficients of a balanced chemical equation Calculation of quantities in chemical reactions

N 2 + H 2  NH 3 Must balance equations correctly 32 Balanced equation can be interpreted in terms of different quantitites. atoms, molecules, moles, mass and volume

N 2 + H 2  NH 3 Must balance equations correctly 32 What are the 6 mole ratios for the reaction? 1 mol N 2 3 mol H 2 1 mol N 2 2 mol NH 3 3 mol H 2 2 mol NH 3 3 mol H 2 1 mol N 2 2 mol NH 3 1 mol N 2 2 mol NH 3 3 mol H 2

N 2 + 3H 2  2NH 3 How many atoms of each? molecules?moles?mass?volume? Mass and atoms must be conserved but not necessarily molecules, fu,moles, or volume

Practice problems Complete p379 #36 write mole ratios Do #40,41,42

4/14/11 N 2(g) + 3H 2(g)  2NH 3(g) How many moles of nitrogen are needed to react with 5.2 moles hydrogen gas? How many moles of ammonia (NH 3 ) can be produced from 54 g of nitrogen? How many grams of hydrogen are needed to produce 100.0 grams of ammonia gas?

Limiting reagent What is it? What is it? The thing (reactant) that runs out first, Just like in a recipe. N 2(g) + 3H 2(g)  2NH 3(g) How many moles of nitrogen are needed to completely react with 15 moles of H 2 in the above reaction ?

Limiting reagent N 2(g) + 3H 2(g)  2NH 3(g) How many grams of nitrogen are needed to completely react with 8 grams of H 2 in the above reaction ? How many grams of NH 3 can be produced in this reaction?

Limiting reagent N 2(g) + 3H 2(g)  2NH 3(g) What is the limiting reagent in the above reaction, if 10 moles of hydrogen gas react with 10 moles of nitrogen gas?

Limiting reagent N 2(g) + 3H 2(g)  2NH 3(g) What is the limiting reagent in the above reaction, if 4 grams of hydrogen gas react with 14 grams of nitrogen gas? How many grams of NH 3 can be produced in this reaction?

Limiting reagent (cooke method) N 2(g) + 3H 2(g)  2NH 3(g) What is the limiting reagent in the above reaction, if 10 moles of hydrogen gas react with 10 moles of nitrogen gas? N2N2 H2H2 L imiting R eagent 1 mol 3 mol 10 mol 1 x x.33

Limiting Reagents 2AgNO 3 + Cu  Cu(NO 3 ) 2 + 2Ag There are 4.3 moles of AgNO 3 and 12.3 moles of Cu. Which is the limiting reagent? There are 4.3 moles of AgNO 3 and 12.3 moles of Cu. Which is the limiting reagent? AgNO 3 Cu L imiting R eagent 2 mol 1 mol 4.3 mol 12.3 mol 2 0.35 AgNO 3 is the limiting reagent. It runs out first.

Limiting Reagents 2AgNO 3 + Cu  Cu(NO 3 ) 2 + 2Ag 2AgNO 3 + Cu  Cu(NO 3 ) 2 + 2Ag There are 500g of AgNO 3 and 1200g of Cu. Which is the limiting reagent? There are 500g of AgNO 3 and 1200g of Cu. Which is the limiting reagent? AgNO 3 Cu L imiting R eagent 2 mol 1 mol 500 g 1 mol 1 169.88 g 1200 g 1 mol 1 63.55 g 2.94 mol 18.9 mol 2 0.15 x x AgNO 3 is the limiting reagent. It runs out first.

Percent Yield 4/13/10 Actual yield X 100 theoretical yield

Limiting reagent N 2(g) + 3H 2(g)  2NH 3(g) How many grams of nitrogen are needed to completely react with 8 grams of H 2 in the above reaction ?

Limiting reagent N 2(g) + 3H 2(g)  2NH 3(g) What is the limiting reagent in the above reaction, if 2 grams of hydrogen gas react with 14 grams of nitrogen gas?

Yeah!TOD 4/15/11 2Al (g) + 3Cl 2(g)  2AlCl 3(g) 1) List all mole ratios. 2)How many moles of aluminum are needed to react with 5.2 moles chlorine gas? 3)How many moles of aluminum chloride (AlCl 3 ) can be produced from 54 g of chlorine?

Practice problems/Homework Complete p370 #25,26,27,28

Lab demo CuCl 2 + Al 

Ticket out the door retake Warm-up 4/15/11 H 2(g) + O 2(g)  H 2 O (g) How many moles of oxygen are needed to react with 3.7 moles hydrogen gas? How many moles of water can be produced from 12.5 g of oxygen? How many grams of hydrogen are needed to produce 67.0 grams of water?

Download ppt "Molarity Lab 4/12/11 Let’s make a solution or 2. 1) With a partner, make 20 milliliters of a 2.0 Molar solution of NaCl. 2)Next, make exactly 175 mL of."

Similar presentations