chemistry 3/24/14 “the key is not the 'will to win'...everybody has that. it is the will...

Chemistry 3/24/14“The key is not the 'will to win'...everybody has that. It is the will to prepare to win that is important.” Bobby Knight

DO NOW:1. In your notes: Write a chemical equation for the following

word equation: 2 slices of bread reacts with 1 slice of cheese and 3 slices of ham to yield 1 sandwich

AGENDA:1. Review midterm exam2. SWBAT identify what a limiting reactant is by preparing for tomorrow’s lab

ANNOUNCEMENT:Science club is meeting Tuesday, March 25. Be ready to discuss research for our dissection!

Do Now:

2 bread + 1 cheese + 3 ham → 1 sandwichIf you have 40 pieces of bread, 12 slices of cheese, and 35 slices of ham, how many sandwiches can you make?

How can you use a mole ratio to determine how many sandwiches can be made?

Mole Ratios

•Coefficients: tell us the MOLE RATIOS used or produced in a chemical reaction

Mole Ratios

•Mole Ratio: –Compares the moles of reactants and products in a chemical equation.–Can be used as conversion factor.

2 bread + 1 cheese + 3 ham 1 sandwich

𝟐𝒎𝒐𝒍 𝒃𝒓𝒆𝒂𝒅𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒅𝒘𝒊𝒄𝒉

𝟏𝒎𝒐𝒍𝒄𝒉𝒆𝒆𝒔𝒆𝑰𝒎𝒐𝒍 𝒔𝒂𝒏𝒘𝒊𝒄𝒉

𝟑𝒎𝒐𝒍𝒉𝒂𝒎𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒅𝒘𝒊𝒄𝒉

𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒅𝒘𝒊𝒄𝒉𝟐𝒎𝒐𝒍 𝒃𝒓𝒆𝒂𝒅

𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒘𝒊𝒄𝒉𝑰𝒎𝒐𝒍𝒄𝒉𝒆𝒆𝒔𝒆

𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒅𝒘𝒊𝒄𝒉𝟑𝒎𝒐𝒍𝒉𝒂𝒎

4 P + 5 O2 2 P2O5

𝟒𝒎𝒐𝒍 𝑷𝟓𝒎𝒐𝒍𝑶𝟐

𝟓𝒎𝒐𝒍𝑶𝟐

𝟒𝒎𝒐𝒍 𝑷

𝟐𝒎𝒐𝒍 𝑷𝟐𝑶𝟓

𝟓𝒎𝒐𝒍𝑶𝟐

𝟓𝒎𝒐𝒍𝑶𝟐

𝟐𝒎𝒐𝒍 𝑷𝟐𝑶𝟓

𝟒𝒎𝒐𝒍 𝑷𝟐𝒎𝒐𝒍 𝑷𝟐𝑶𝟓

𝟐𝒎𝒐𝒍 𝑷𝟐𝑶𝟓

𝟒𝒎𝒐𝒍 𝑷

2 bread + 1 cheese + 3 ham 1 sandwich

𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒅𝒘𝒊𝒄𝒉𝟐𝒎𝒐𝒍 𝒃𝒓𝒆𝒂𝒅

𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒅𝒘𝒊𝒄𝒉𝑰𝒎𝒐𝒍𝒄𝒉𝒆𝒆𝒔𝒆

𝟏𝒎𝒐𝒍 𝒔𝒂𝒏𝒘𝒊𝒄𝒉𝟑𝒎𝒐𝒍 𝒉𝒂𝒎

40 mol bread x 12 mol cheese x35 mol ham x

= 40Sand.= 12Sand.= 11Sand.

Important definition

Ham is your limiting reactant for this chemical reaction.Limiting Reactant: A reactant that is totally consumed during a chemical reaction. Limits the extent of the reaction, and determines the amount of product.

CHALK LAB

-Work in POGIL groups of four-You will produce chalk (CaCO3) by combining CaCl2 and Na2CO3 in a double replacement reaction

Important Definition

Double replacement reaction:A chemical reaction that involves the exchange of ions between two compounds and produces either a precipitate, a gas, or water

Important Definition

Precipitate:A solid produced during a chemical reaction in a solution. Usually denoted with a subscript: (s) for “solid” in a chemical equation.

Questions

1. If I want to make 2.00 grams of chalk, how much of each reactant do I need?

2. Which of the reactants in the balanced chemical equation is the limiting reactant?

Procedure:

1. Balance the chemical equation that represents the chemical reaction for the lab

2. Calculate the amount in grams of sodium carbonate to be used in order to obtain 2.00g of calcium carbonate.

Procedure:

3. Calculate the amount in grams of calcium chloride to be used in order to obtain 2.00g of calcium carbonate.

4. Put on your safety goggles.

5. Obtain two clean beakers.

Procedure:

6. Obtain the correct amounts (calculated in the pre-lab) of calcium chloride and sodium carbonate. Tare (zero) the balance with the beaker on the balance and then slowly add the chemical until you have the desired amount. Enter these masses in your data table.

7. Add enough distilled water to dissolve the calcium chloride. Try to use a small amount of water so your filtration does not take too long. Stir.

Important Definition

Filtration:A technique that uses a porous barrier to separate a solid from a liquid

Procedure:

Procedure:

8. Add enough distilled water to dissolve the sodium carbonate. Stir. Try to use a small amount of water so your filtration does not take too long.9. Pour the calcium chloride solution into the beaker containing the sodium carbonate solution. Record your observations.

Procedure:

10. While waiting for the solid to settle, find the mass of a piece of filter paper. Record the mass in your data table. 11. Set up a funnel, filter paper, and beaker. Wet the filter paper with a small amount of distilled water.

Procedure:

Procedure:

12. Pour the contents of the beaker slowly into the funnel. Be careful as you pour, so none of the solid flows out of the filter paper or funnel. Rinse inside the beaker with distilled water to remove any more solid.

Procedure:

13 . Once all of the solid is on the filter paper and the liquid has all drained through into the beaker, carefully remove the filter paper from the funnel and set into a 150 mL beaker that is labeled with your name and period. You will take your final mass tomorrow after the product is allowed to dry overnight.

Procedure:

12 . Clean Up!