Monthly Archives: September 2016

G12 Cover

1. Calculate concentration of your sodium carbonate solution

Make sure you propagate the error.  Check with your partner that you have the same number.   The concentration if calculated properly should have at least 3 dps (possibly 4) according to the measurement uncertainty.

2.  Titration calculations

You will finish your titration next week.  This week you will practice some titration calculations.  You will find them on the Google+.

3.  Trends in the oxides of period 3

Complete the hand out.  You will need to fill in the :

  1. Name of the oxide (IUPAC)
  2. What state it would be in at room temperature (solid, liquid, gas).
  3. If it conducts electricity when molten
  4. What type(s) of bonding are present?  Ionic, covalent and any intermolecular forces?
  5. Write the equation for the reaction with water.
  6. From the equation, determine if the oxide is acidic, basic or amphoteric!

4. Study / Work on Final of IA

If you have your draft back, you can use this time to work on the final copy.  If you don’t have the draft back, you could use the rest of the time to do your own private study for chemistry.  This could include:

  • making a quizlet list
  • learning a quizlet list
  • practicing questions from old topics on the google+ or elsewhere
  • reading ahead in acids and bases and making your own notes

G11 Cover

1. Teach Kaishyu!

Make sure Kaishyu is up to speed with Bond Enthalpies.  Give him the theory and explanation and help him through the questions we did last lesson found on the Google +.

2.  Bond enthalpy practice

Take a Bond Enthalpy Calculations sheet.  Do the first 5 questions.  Check that everyone agrees with your answers.

Chose any other 5 questions to do on that sheet.  (Make sure you all choose the same 5).  Share and discuss your answers.

3.  Chapter 5 Review

From your textbook, complete Q33 – 38 and check your answers.

Read and take your own notes from the section on Ozone Depletion from the text.

Congratulations – you have finished your first SL topic!

The Gas Laws

1.  Avagadro’s Law

Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.

Take a look at one or more of the following sources that explain this law.  Alternatively, read chapter 1.3 in your textbook.

✍  Make your own summary in your notebook.

Avagadro’s Law Sources

✍  Now apply the Law by completing these questions:

Avogadro’s Law questions and their answers.
Find more questions in your textbook.

2. More Gas Laws

You can use the PhET simulation below to see the various changes in temperature, pressure and volume of a fixed amount of gas when you change one of these variables.

Gas Properties

Click to Run

 

A summary of the various gas laws defining the relationships between volume, temperature and pressure are found below.

V = volume in dm3
T = temperature in K
P = pressure in kPa

Note that these relationships are not given to you in the data booklet.

These laws can be represented graphically too.

Read the section in your textbook, and look at the sites mentioned for Avogadro’s Law to find more information if needed.

✍  Write a summary in your notebook.

3. Kinetic Theory of Gases and the Ideal Gas Law

The kinetic theory describes a gas as a large number of submicroscopic particles (atoms or molecules), all of which are in constant rapid motion that has randomness arising from their many collisions with each other and with the walls of the container.

✍  The kinetic theory of gases is used to describe the motion and behaviour of an ideal gas.  Using your text and other relevant sources, describe the differences between an ideal gas and a real gas in your notebook.

The molar volume of any gas at STP (standard temperature and pressure) is represented below.

Screen Shot 2016-09-05 at 1.16.53 PM

Warning!Warning!Warning!Warning!Warning!Warning!Warning!Warning!Warning!
Many sources quote the molar volume of a gas as 22.4 dm3.  This is using a standard pressure of 101.3 kPa NOT 100 kPa which is the new standard adopted by the IB!  Beware of past paper questions using the old value!  The new value has been used only since the 2016 exams!  If in doubt, check your data booklet – the value is quoted there as 22.7 dm3.

Combining all the equations so far, we can derive the ideal gas equation.  This is in your data booklet as is the value for R which is the ideal gas constant.  Check to make sure you know where to find these.

You will need to be able to solve problems based on these laws.  Once you feel comfortable with them and you have read and taken relevant notes from chapter 1.3 in your text, you can try the following problems.

Problems
Answers (remember that some of these might use 22.4 instead of 22.7 as the molar volume of an ideal gas at STP.)