## Q3: week 8 – 3/27 –  3/31

” The first day of class should connect to the last day and every day in between!”

Please check Power School for accuracy!

Everyone needs to join Remind for class.  Click me to sign up.

3/27 – Monday – “B” Day –

Main focus:

a)  To review the concepts of Molarity, Part per million, percent by mass of a solution, formula mass, and precipitation reactions

Period  8:

1.  To review the Solubility CAT 2.

Period  9:

1.  To complete the Solubility DOG.

____________________________________________________

3/27 – Monday’s Homework: –

1. Study for the Solubility DOG.

Solubility CAT 1 – Key.pdf

Solubility CAT 2 review worksheet .pdf

Solubility CAT 2 review worksheet KEY.pdf

Mole, formula mass, Molarity Notes KEY.pdf

Solubility CAT 2 – Key.pdf

Main focus:

a) To Complete the solubility DOG

b) To begin the percent by mass of a hydrate lab.

Period  9:

1.  Start the heating of a hydrate for Lab 17.

2. Complete Solubility Dog while heating.

3.  Find the final mass of the dried hydrate (anhydrate).

Why did we keep heating and re-weighing?

____________________________________________________

3/28 – Tuesday’s Homework: –

1. Complete the worksheet with the video posted below.  When instructed please check the key.

Hydrate Intro worksheet.pdf

Hydrate Intro worksheet Key.pdf

I will collect it tomorrow for a quiz grade.

2. Complete the Form Below based on the the topics learned in the video. Most topics are really not new just applied to a new scenario.

1 : Hydrate Intro Worksheet Review –

2 : Hydrate Form: THERE IS ONLY ! SUBMISSION TONIGHT!

3/29 – Wednesday – A Day –

Main focus:

a) To calculate the percent by mass of an element in a compound

b) To calculate the percent by mass water in a hydrate experimentally and theoretically

c) To calculate the empirical and molecular formula using percent by mass.

Period  8:

1.  Start Lab 18 by heating the hydrate:

Lab 18 – Empirical Formula of a Hydrate .pdf

2. Complete Solubility DOG while heating.

3.  Multiple Heatings

4.  Calculate the empirical formula and molecular formula Lesson

empiri&molec ditto hydrate combination 1314 .pdf

empiri&molec ditto hydrate combination regents 1314 COMPLETE key .pdf

Period  9:

1.  Complete Labs 16,17 and maybe 18.

2. Empirical formula from grams or percentage,

Todays Lesson Empirical and Molecular formula determination –

______________________

Lab 17, 18 – Percent mass of water in a Hydrate

Let’s look at an ionic crystal that has no water called anhydrate.

Lets look at copper (II) sulphate : CuSO4  :
 This image was build by X-ray imaging of salt. Now it is more complex than the crystal above for NaCl because we have a polyatomic ion in the crystal. The Yellow is the Sulfur attached to 4 oxygens (red).  The brown color (i think its brown) is the copper. Notice regular repeating pattern.The sticks represent the bonds or the attractions between the ions. Its hard but if look inside the crystal there is one Cu per sulfate ion.

Lets look at the formula of the hydrate of the same salt : copper (II) sulphate pentahydrate:

 CuSO4 ● 5H2O Notice the Dot between anhydrate and water.  This Dot means “WITH” and not to multiply.    There are exactly 5 water molecules for every 1 Cu+2 and  1 SO4-2 in the crystal.

Lets look at the crystal formation of copper (II) sulphate pentahydrate:
 You will notice that water (it has 2 white hydrogen atoms) molecules are situated inside the crystals at particular regions in the crystal in exact ratios.  This is a fixed ratio (stoichiometric ratio). It is hard but you can see the 5 water molecules per 1 copper ion and 1 sulfate ion. What makes it hard is that the crystal repeats in all directions. The water can be removed from the salt by heating it.
CuSO4 • 5H20   ——->    CuSO4  (s)     +      5H20  (g)                                                                                                                               Heat
Today we will be able to do the following:
a) Determine. the mass of your annhydrate (dried hydrate)
b) Determine the mass of the water (THAT was in your crystal)
c)  calculate the experimental percent by mass of water:

% by mass =  Mass of the part (mass of water missing)         x     100
Mass of the whole (mass of original hydrate)

d)  calculate the Theoretical percent by mass of water using the chemical formula of the hydrate:

CuSO4 • 5H20

Given the formula above, determine the percent by mass of water of the hydrate:

Assume you have 1 mole of CuSO4 • 5H20:

Thus in 1 mole of the hydrate you have 5 moles of water:

For every one (CuSO4 • 5H20) you have 5 moles of water.

1               :               5

Ratios of how many!!! This is why we need a mole theory!

% by massMass of the part (mass of 5 moles of water)         x     100
Mass of the whole (mass of 1 mole of hydrate)

*Mass of 1 mole of any compound (with a unique chemical formula) is the sum of the atomic masses of all atoms in the formula or molecule. You need the periodic table!

__________________________________________________________
3/29 –  Wednesday – Homework: –

1. Make one more submission to yesterday’s form.  It is not on auto reply and you have only 1 submission.

3/30- Thursday “A” Day

Main focus:

a) To write a empirical formula for a compound given percent by mass data.

b) To write the empirical formula of a hydrate given its percent by mass data.

Period  9:

1. Make a 3rd heating for the Magnesium Hydrate lab.

2. Empirical Formula lesson.

empiri&molec ditto hydrate combination 1314 .pdf

empiri&molec ditto hydrate combination regents 1314 COMPLETE key .pdf

3.  Calculate the empirical formula of the magnesium hydrate (lab 18)

Lab 18 – Empirical Formula of a Hydrate .pdf

__________________________________________________________________

3/30 –  Thursday – “A” Day homework:

1. Complete question 2,3, and 8 on the worksheet that we started in class today and review with the key below.

empiri&molec ditto hydrate combination 1314 .pdf

empiri&molec ditto hydrate combination regents 1314 COMPLETE key .pdf

I may collect something tomorrow!

_______________________________________________________________________________________
Connect

Todays Lesson Empirical and Molecular formula determination –

3/31 – Friday – “B” Day –

Main focus:

a) To practice and review percent by mass calculations.

b). Complete our hydrate labs

Period  8:

1. Complete the conclusion questions from Lab 17.

2.  To write the conclusion for lab 17.

a)  Read your objectives and write about what you calculated. – percent by mass of water theoretical and experimental                        values.

b)  What was the percent error?  Why was it small or large? What were the errors in this lab?

3. Complete Lab 18 by calculating the empirical (lowest ratio) formula for magnesium sulfate hydrate.

MgSO4· ? H2O

Period  9:

1. Print out the worksheet or just use a separate piece of paper.

HW questions 1 regents 2015 .pdf

2. Complete the form below:

Math Form 1:

C

3/31 –  Friday Homework: –

1 There is no homework this weekend.

______________________________________________________________________

Connect