" The Big Picture!" by Mr C

Last lessons Objectives

Pretest Evaluation

3 Class Average 64%

Evaluations

Today’s Objective

Final Prep for Exam

Class Average

60%

Topic

Number One

There was a total of only 8 Questions where folks had problems! I included three difficult questions and more harder average questions and the class average went up! So we are going in the right direction.

Lets review the eight questions

Error One..Please read the book and my notes

All synthesis reactions do not convert elements to a single product!

Synthesis reactions can have elements as a reactant but they can also combine compounds and elements or compounds and compounds to product a single product.

Error Two

When we label a substance, element or compound you need to consider what state of matter it is in (Solid, Liquid and Gas). Oxygen, Carbon Dioxide and Nitrogen can be all three states of matter depending upon the temperature. The question asked how many products should be labeled as a gas. One product, water vapour, is a gas! The word vapour is a molecule in a gas state. While vaporub goes on as a solid..it put vapour smell into the air.

Error Three

Organic chem question. Which element (nonmetal) will form a covalent compound with the most Hydrogen. Sodium is not a non metal..so that is wrong. Oxygen only needs two electrons and Nitrogen only needs three electron, yet Carbon needs four electrons to fill it’s outer orbital and so it will need four hydrogen.

Error Four

Organic Chem Question: When added to water, which will lower ph.

Here is a clue, when you blow bubbles into water you carbonate the water. That carbonate react with water to form carbonic acid. So which compound is a covalent compound with oxgen? Sodium Oxide..nope.

Sodium Hydroxide? Nope. Magnesium oxide? Nope. Nitrogen Oxide..

Bing! Correct. Water is a universal solvent yet it can form acids with covalent oxides.

Error Five

If you combine two aqueous solution together and you get a reaction, it usually is in the form of precipitation. Precipitate means a solid. The big clue is including the state of matter in the reaction. Two aqueous solutions..make a solid…now..is it a double or single replacement reaction?

Error 6

Hmm..this is a covalent question. Two nonmetals combine, so how do we name the molecule? Remember that if the first nonmetal is a single atom…say..Carbon and the second is Oxygen..we have carbon dioxide not monocarbon dioxide. The vocab word is “prefixes”.

Error 7

Another covalent compound question. Two nonmetals combine to form a compound..no it is not the beginning of a bad joke. Two nonmetals will form a covalent compound! They always share electrons. It is just so..two nonmetal..covalent..share!

Error 8

Back to chapter four! The element symbol..say…”C” in a Lewis model represents the nucleus and the inner shell electrons! Why do we use a Lewis model? To show bonding in the outer orbital! Why do we use Bohr? To show atom structure? Why bother? Just because you wear Nikes doesn’t mean you can play basketball..what is inside is a lot different that what is on the outside.

Increasing surface area is thought to increase the rate of chemical reactions because it increases the number of collisions between reactant particles!

Topic

Number Two

So how did you do? Pretty much the same mark for most folks..

Get some sleep..think positive or proton thoughts and drink no caffeine after seven!

Topic

Number Three

Take Home Message

In practices we show more effort and play harder so that in the actual game, we excel. Walk the walk!

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