Login | Register

Welcome, Guest. Please login or register.

February 17, 2020, 03:10:50 pm

Author Topic: Convert content to questions (chem)  (Read 415 times)  Share 

0 Members and 1 Guest are viewing this topic.

insanipi

  • Moderator
  • ATAR Notes Legend
  • *****
  • Posts: 3912
  • "A Bit of Chaos"
  • Respect: +2564
Convert content to questions (chem)
« on: January 07, 2019, 02:20:38 pm »
+7
Hey there!

As you probably already know, practice questions are an EXTREMELY useful form of revision, and that it's generally best practice to complete them throughout the year, rather than waiting until the end; not surprisingly, this can also include making your own questions!

Remember that answering questions the way VCAA likes (such as using the provided units, showing substitution equations/working out, displaying correct # of sigfigs, and knowing key question terms) is a valuable habit to ingrain as well as understanding and knowing the content!

I'd encourage everyone to make a few questions and contribute them to this thread - if you're unsure about your question or answer post anyway (feel free to note any uncertainty) and other users will check it :)

Guidelines:
- can be of any form (diagram, multiple choice, short answer, other)
- put the answer in a spoiler
- the VCE study design, QCE syllabus and HSC syllabus  are great resources for reminding you of what topics you could write on.
« Last Edit: January 19, 2020, 11:00:32 pm by Bri MT »
2017-2019: Bachelor of Pharmaceutical Science (Formulation Science)
2020: Bachelor of Pharmaceutical Science (Honours) (Drug Delivery, Disposition and Dynamics- focusing on lipid gene delivery formulation)
Follow my uni journey here!

Join us for the science games!

laura_

  • VIC MVP - 2019
  • Part of the furniture
  • *****
  • Posts: 1329
  • happy, free, confused and lonely at the same time
  • Respect: +728
Re: Convert content to questions (chem)
« Reply #1 on: January 21, 2020, 09:11:51 pm »
+3
Atomic Theory (VCE and QCE Unit 1)
1) What is the formula for the maximum number of electrons that a shell can hold? (1)
Spoiler
A=2*n^2
For example: In shell 3, there would be 2*3^2 (2*9) electrons. That is 18 electrons.

2) Define valence electrons. (1)
Spoiler
Valence electrons are electrons that are found in the last shell that is occupied by any electrons in an atom.

3) Explain why noble gasses are called inert in relation to valence electrons. (3)
Spoiler
Noble gasses are called inert. That means that they are unreactive. (1 mark for defining the work inert.) This is due to the fact that they have a full shell of valence electrons. (1) It is the most energetically stable for an electron to have a full outer shell of electrons. (1) When an atom exists in a state where the valence shell is not completely full, it will try to gain or lose electrons in order to reach this state by reacting with other elements. Noble gasses have a full valence shell so they do not need to react in order to reach this state.

4) Write out the full electronic configuration for the element Bromide (35). (1)
Spoiler
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p5 (the last number of each set of three should be written as an indice (power))

5) Explain why copper and chromium do not adhere to the Schrodinger model of the atom? (2)
Spoiler
Copper and chromium are exceptions to the Schrodinger model of the atom because of the same reason. That is, a completely full or half-full d subshell is more stable than a partially full d subshell. (1) For copper instead of having a 3d9 4s2 configuration (as expected) it has a 3s10 4s1 configuration (with a full d subshell).  For chromium instead of being 3d4 4s2 it is 3d5 4s1 so that the d shell is half full rather than partially filled.
but thereís only so much shrinking a girl can do before she disappears

andrew674307

  • Adventurer
  • *
  • Posts: 7
  • qce 2020 fam
  • Respect: +4
Re: Convert content to questions (chem)
« Reply #2 on: January 21, 2020, 09:51:44 pm »
+3
Here are some questions related to Unit 3 Topic 1 of the QCE Chemistry syllabus we learnt last term

What is the difference between an open and closed system?
Spoiler
Open systems exchange both energy and matter with the surroundings, whereas closed systems exchange only energy.
Equilibriums are only established in:
a) Open systems
b) Closed systems
c) Both open and closed systems
Spoiler
b) closed systems, because in open systems, reactants and products may be lost during a reaction

Define Le Chatelierís Principle
Spoiler
If a stress is applied to a system at equilibrium, the system will act to oppose the stress and restore the equilibrium

QCE 2020
Chem | Bio | Methods | Specialist | French | English

ArtyDreams

  • MOTM: Jan 20
  • Trendsetter
  • **
  • Posts: 198
  • Fly against the wind. Not with it.
  • Respect: +202
Re: Convert content to questions (chem)
« Reply #3 on: January 22, 2020, 07:20:35 pm »
+5
VCE Unit 3 AOS 1

Q1. Define the term 'carbon neutral,' and provide an example of a fuel that can be classified as this.
Answer
Carbon neutral is a characteristic given to a fuel that does not result in the net production of carbon dioxide, from source or production. Bioethanol produces carbon dioxide in its formation, but the plants absorb most of this through their process of photosynthesis, meaning that bioethanol is relatively carbon neutral.

Q2. Discuss the characteristic 'hygroscopic' in relation to biodiesel.
Answer
The COO- groups in biodiesel can form hydrogen bonds with water molecules, making the substance hygroscopic. Hyroscopic is the name given to a substance that can absorb water. Therefore, biodiesel has the ability to absorb water, and can therefore be stores for a longer period of time.

Q3. Discuss the benefits of using biofuels as a source of energy production.

Answer
Biofuels are a renewable source of energy, as it is produced by plant matter. Plants grow in short time periods, meaning that the fuels can easily be replenished. Biofuels are relatively carbon neutral, as the plants take the excess carbon dioxide produced and use it for their process of photosynthesis. The production of biofuels produces less particulate matter, which is more environmentaly healthy. It is easy to source materials for their creation, as they mainly require land and water. 

Q4. In reference to the electrochemical series, when will a spontaneous reaction occur?
Answer
A spontaneous reaction will occur when the strongest oxidising agent is above the strongest reducing agent in the electrochemical series. 

Q5. What is the oxidation number of Sulfur, in Na2SO4?
Answer
The overall charge of the molecule is 0, and the charge of Na is +1, so:
(+1)(2) + x + (-2)(4) = 0
+2 + x - 8 = 0
x = 8 - 2
x = +6
Therefore, the oxidation number of sulphur is +6
 


(Mods, feel free to edit if anything doesn't make sense, I'm still a little rusty with these topics)
Also, note to anyone thinking of writing questions, or having doubts: just GO for it!! I was a little nervous going inot this, as I didn't think my knowledge was enough, but it is actually so helpful doing this! It helps you find gaps in your knowledge, but also helps enhance it. After all, if you know how examiners write questions, you're more likely to pay more detail when answering them too  ;D
« Last Edit: January 22, 2020, 07:31:13 pm by ArtyDreams »
the world is too heavy to carry alone.

VCE Class of 2020 

My Short Guide to Mathematical Methods
My VCE Journey Journal