# Chapter 25: Essential Calorimetry Formulae

Calorimetry can be a confusing topic. Avoid common errors by following these essential tips:

1. Always label the units of E (kJ or J) above the E. This is the most common source of error in calorimetry calculations. Try this quick way to remember the required units of E: If there’s ΔH in the equation, the units are kJ; otherwise, the units are J.
2. In E=mcΔT, all the variables refer to the mass of water being heated. A common error among students is to use the mass of limiting reactant instead of the mass of water. Generally, m in this equation is 100 g or a similar round number.
3. Never convert ΔT to kelvin. Temperature changes are the same in kelvin and celcius… never add 273 when finding ΔT.
4. No calibration step? Use m×c instead. Because E=mcΔT and E=CfΔT, it therefore follows that Cf ≡ m×c. For example, if we’re heating a 100.0 g of water without a Cf, we should use Cf = 100×4.18 = 418 J K-1 instead.
5. In ΔH = E/n, n denotes the number of moles of limiting reactant. Never add up the number of moles of reactants: use the number of moles of limiting reagent only.
6. Calculate twice. Students most often make mistakes when converting hours or days into seconds. Many answers are therefore wrong by a factor of 60. Do your calculations twice: once while doing the question and again when you check over your answers at the end of the SAC or examination.
7. Know a ballpark figure. Neutralisation and solubility reactions tend to have 2-digit ΔH values; combustion reactions tend to have a 3-digit ΔH and explosive reactions tend to have a 4-digit  ΔH. If you get a 5-digit ΔH value, you’ve probably forgotten to convert your answer into kilojoules!
8. Remember the ‘+’ or ‘-‘ sign! The calculator doesn’t know whether the answer should be positive or negative. Think about it yourself instead: endothermic reactions need a ‘+’ sign and exothermic need a ‘-‘ sign. VCAA awards a whole mark for getting the ‘+’ or ‘-‘ sign correct! It’s possibly the easiest mark in the whole paper.

Consider getting a home tutor who can answer your questions and explain difficult concepts to you. Students learn much faster with a tutor than on their own.

# How they did it: Tips from 99.95 students

### Tips from Izabella Bratek at Academyplus.com.au

1. Develop excellent study skills. Cultivate ideal study habits such as waking up early, reading your notes before school, doing all homework on time and studying even when there’s no homework set.

2. Stay committed and know what you want and WHY. People who know why they do what they do are far more likely to persist and put in the huge number of hours required to excel at that particular skill. All successful people were driven by a higher. Find your why and you’ll feel more motivated to study VCE.

3. Keep motivation levels high and consistent throughout the year. Remind yourself constantly why you’re studying the VCE subjcets you’ve chosen.

4. Do not “over-indulge” in VCE tutoring. Your tutors and teachers can only take you so far. The highest-achieving students are those who are self-motivated: they push themselves and study even when nobody asked them to. Become self-motivated and use your tutoring time wisely to maximise your performance in VCE exams.

### Tips from Alastair Weng at Cloudninetutoring.com

1. Maintain good study habits. Get more information on study habits here.

2. Keep a balanced life. Stay healthy by socialising and exercising regularly. Don’t sacrifice health for your ATAR: a healthy body helps maintain a healthy mind.

3. No regrets. Remember that the sacrifices you make today will pay off in the future.

### Tips from Akhil on the BoredofStudies.org forum

1. Stay a whole module ahead.

2. There are two things you need to do: make great notes and do practice questions.

3. Build on your notes from external sources (other people’s notes and the textbook)

4. Mark your questions – or get them marked! Akhil says that while it’s an excellent learning exercise to practice marking questions by yourself, it’s also necessary to get your practice papers and Checkpoints questions marked by a teacher or tutor because they’ll be more vigilant with sticking to the marking scheme and can pick up slight errors in wording that are easy to miss if you mark your own work.

### Want more? Try How to Get Ahead in VCE Chemistry

Do you know of any more study tips? Are there any crucial tips missing from this list? Post them into the comments section below.

# How to get ahead in VCE Chemistry

#### 1. Do all the required work for your course.

This includes the required textbook questions, any weekly quizzes and worksheets or booklets that are provided by your teacher.

Refer to the course outline and read the textbook chapters before we study them in class. It makes a huge difference to your level of understanding.

Compare your answers in the weekly Chemistry quizzes with the ideal answers on the examiners’ reports. (These will be sent out after each quiz has been completed.) Textbook questions are a bit like reading comprehension questions: they test your understanding of what you’ve just read in the textbook. Weekly quizzes are written in a much more similar style to the VCE Chemistry examination you’ll sit at the end of the year.

#### 4. Re-do any SACs that you did not get 80% in

Ask your teacher for a SAC follow-up exercise if you achieved less than 80% in any SAC. Hand in the SAC follow-up exercise to your teacher when completed for marking. (Only your first SAC score will count; however, this strategy is an excellent way of highlighting areas in need of improvement, and then improving on them.)

#### 5. Complete Checkpoints Questions

Your goal is to complete all of the questions in the Checkpoints book before 20 July 2015. Complete Checkpoints questions on the topics you study as you progress through the year.

#### 6. Complete Dimensions worksheets

Your teacher will sometimes set Dimensions worksheets as an assignment in your VCE Chemistry course. You can always ask your teacher for extra Dimensions worksheets. Note that some of the questions in Dimensions worksheets extend a little further than the scope of our VCE study design.

#### 7. Refer to additional textbooks (and do some of the questions)

Use additional textbooks for alternative explanations of the same topics. Please don’t use Google to find Chemistry information because about a third of the results are awful (answers.com and answers.yahoo.com are two such examples). Use HeinemannDimensions and StudyON instead: these are the three best textbooks for our course. Complete questions from these textbooks for additional practice on certain topics as required.

#### 8. Complete past examination papers

By June 2015, you will have finished studying all of Unit 3. You will therefore be able to complete Unit 3 practice examination papers from VCAA’s website (or from your teacher/tutor) by this time. Complete past examination papers in exam-like conditions and check your answers critically using the examiners’ reports provided.

If you get stuck, just ask your teacher/tutor for help. Send them an email saying “Sir, I have no idea how to answer this question!” or knock on their office door for advice. They’re always happy to help!

Remember the 5-minute rule. If you’re stuck (i.e. making no progress) on a single question for more than 5 minutes, ask for help and move on. Re-do the question once your teacher or tutor has responded with tips as to how to answer the question.

Do you know of any more study tips that aren’t in this list? Add them in the comments section below.

# How to Make Time for 100 Days of Revision

Students who aim for a Study Score of 42 or above complete at least 20 practice papers for each subject they’re studying and correct them critically before examinations begin. High-achieving students print these 20 practice papers and make a detailed revision schedule before full-time revision sets in.

Learn how to make a quality revision timetable here.

Twenty practice papers, with proper correction and revision of theory, require 20 days to complete. A student studying 5 VCE subjects therefore needs 100 Days of Revision before their examinations begin.

VCE exams begin on October 28th, 2015, and 100 Days of Revision therefore begins on July 20th, 2015 for students who want to excel. Most schools plan to finish teaching Unit 4 at the end of August, which is just 40 days before the final examination. Forty days allows you only 8 days of revision for each of your 5 VCE subjects, and this simply isn’t enough practice for students who want to excel.

The best way to make time for 100 Days of Revision is to study Unit 4’s Area of Study 2 during this upcoming Easter Holiday.

In this upcoming Easter Holiday, by yourself, or with the help of a home tutor, you can study the topics that your school has planned to teach after July 20th, 2015. Typically, this is Unit 4’s Area of Study 2 (Chapters 23 to 28 in the Heinemann Chemistry 2 textbook). By studying this topic early, you’ll save time later in the year, which will allow you to complete 20 practice exams per subject instead of using that time to learn new theory.

### Easter Holiday Tutoring 2015

If you want to learn Unit 4’s Area of Study 2 this holiday, and free up your homework schedule later in the year, get in touch for a short-term set of tutoring sessions in April 2015. I am offering new students a short-term Easter Holiday tutoring package for \$300.

The \$300 tutoring package includes:

• Chemistry Unit 3 & 4 diagnostic test;
• Quizzes based on knowledge areas that need to be improved upon (as identified in the diagnostic test);
• Three home tutoring sessions of 2 hours each, which includes:
• Critical review of the student’s homework answers;
• 1-to-1 teaching of Unit 4 Area of Study 2 (Chapters 23-28) with homework exercises and quizzes;
• Answering any Chemistry questions the student has accumulated while doing homework exercises.
• Personalised Chemistry study timetable for the whole year; and
• 24/7 email and phone support for the duration of the Easter Holiday.

The program includes 6 hours of home tutoring and requires 15 to 18 hours of self-study to be completed by the student during the holiday.

Get ahead in Chemistry this Easter. I am available for VCE Chemistry tutoring on the following dates and times.

Monday 30th March 2015 to Friday 3rd March 2015: 9am – 5pm daily
Monday 6th April 2015 to Friday 10th March 2015: 9am – 5pm daily

*UPDATE: I am now fully booked for the 2015 Easter Holiday. Fill in the contact form below to enquire about term-time tutoring at evenings and weekends.

Request VCE Chemistry tutoring using this online form.

# How to use a Textbook: 6 Rules to Follow

Anyone who’s spent time in a classroom knows that in any academic subject, the student who reads the textbook several times from cover to cover and makes colourful, organised notes all over it is going to excel in examinations. For this reason, I’ve been trying to get students reading their textbooks (and making great notes on them) almost as long as I’ve been teaching (since 2006). Glancing your eyes over the words in a textbook isn’t enough. How should you use a textbook properly, in any subject? There are six rules you need to follow.

#### 1. Make notes all over your textbook

The signs of a well-used textbook are obvious: it should be inked heavily with a student’s own notes, the cover should be wrinkled and torn, and there should be at least three different brands of sticky tape holding the book together. It should flex open at 180 degrees with ease, exposing the sturdy threads of spine that prevent it from falling apart. Textbooks are designed to be used! A pristine textbook is the hallmark of a student who doesn’t study. Treat your textbook as your own, and prove that you’ve read it by plastering it with your own notes. Taking notes while you read has been proven to increase comprehension levels by up to 50%… and it makes revising much easier, too. (Just re-read your notes!) What do great textbook notes look like? In all the important sections (and that’s most sections), you should draw a horizontal line in the margin to separate each paragraph. Each paragraph should be summarised in eight words or fewer in the resulting spaces. (See next week’s post on How to Make Great Notes.)

#### 2. Translate key words in your textbook

If you’re studying in a second language, or if you speak more than one language, it will help you to translate key terms into your first language in your textbook. Circle important new words and phrases in the textbook and write the words in your first language beside them.

#### 3. Build vocabulary lists & concept lists based on what you read in the textbook

Vocabulary lists need to contain three things: the word in English, the definition in English and the word in your first language (if not English). Vocabulary lists relevant to the topic you’re studying need to be placed large in prominent places: your bedroom wall (if you’re a student) or on the classroom wall (if you’re a teacher). Build word lists and learn these vocabulary lists using spaced repetition software such as Pleco for iOS or ProVoc for Mac. These apps will quiz you on the vocabulary you’ve been reading at exactly the best time-intervals to ensure you beat the famous “Ebbinghaus forgetting curve”!

#### 4. Highlight your textbook carefully

Highlight important concepts, but don’t go overboard. If you highlight everything, nothing stands out! Use your highlighter and your pen in approximately a 1:1 ratio: they should occupy approximately the same surface area on each page. The best use of a highlighter is to highlight not only key sentences in the book, but also to highlight important notes and summaries that you’ve made yourself. Key things to highlight in a Chemistry textbook, for example:

• Formulae that need to be learned (lead-acid battery half-equations)
• Ions (their names, formulae, charges and colours)
• Acronyms and mnemonics that you’ve created from bullet lists
• Phrases that examiners really care about (“carbon-carbon double bonds” and “alternative reaction pathway”, for example)

#### 5. Make your own notes on paper using the textbook and external sources

Learning is consolidated further in your mind when you translate the notes you made in the textbook margins to make your own hand-written notes on paper. Make a first set of notes on A4 paper. Use a logical colour scheme and concise language and diagrams to consolidate the key information. Use the textbook as the basis for at least 90% for your notes, but also add information (no more than 10%) from other textbooks, news articles and examiners’ reports. Keep your notes safe, organised and visible. Hand-write your notes! Research has shown that people consolidate much more of the information they’ve read into their long-term memory when they hand-write their notes than when they use a computer to type them up. There are several theories that attempt to explain why: the most convincing of these are that computers can be distracting, that typing requires less hand-to-eye coordination than writing, and that typing is slower than writing (if we include colours, diagrams and large amounts of superscript, subscript and the special symbols required for Chemistry). Always hand-write your notes.

#### 6. Always know the textbook references for your current topic of study

Not all teachers give textbook references for the topics they’re teaching in class. But knowing the textbook reference is crucial if students want to review what they’ve learned after the lesson. How can you make your own notes or do further reading if you don’t have a textbook reference? Even worse, many teachers provide students with their own notes, summaries or PowerPoint slides that accompany a lesson. I’m strongly against this. Learning happens in the act of taking great notes, and a teacher who gives their students pre-made notes is depriving their students of the opportunity to learn.

Learning happens in the act of taking notes, and a teacher who gives their students pre-made notes is depriving their students of the opportunity to learn.

If your teacher gives you notes or PowerPoint slides, don’t use them. Kindly ask your teacher for a textbook reference and make your own notes directly from the textbook instead. The textbook will always be more coherent, more comprehensive and more correct than any notes that your teacher distributes in class. For more information, watch this 10-minute clip from ThePenguinProf: https://www.youtube.com/watch?v=xOlJiMKEjpY

# The 8 Benefits of Home Tutoring (VCE Chemistry)

If you’re looking to boost your Study Score in VCE Chemistry, you should consider hiring a home tutor. Home tutoring provides quality contact time that often isn’t available in school. Home tutoring has eight main benefits:

#### 1. Students get a thorough review of what they’ve learned in class with a home tutor

Studies show that a student who leaves a class without having made any notes is able to recall about 10% of what was taught as they leave the classroom. Spaced repetition reviews with a home tutor can increase memory recall of knowledge being taught to well over 80%. By remembering more of the course content, students are primed with a foundation to understand and apply that knowledge much more easily.

Tutors can also explain concepts much faster and more succinctly than teachers in the classroom because they’re working in a one-to-one environment. Without distractions, and without having to divide their attention between 20 or more students, a home tutor can explain clearly in ten minutes what might take a whole lesson if taught by a teacher in a classroom.

#### 2. Students are more motivated to do their homework with the guidance of a home tutor

Students who work on homework tasks with a home tutor tend to stay focussed for longer periods of time than those who don’t. With a home tutor, students can ask questions while doing their homework and spend less time getting ‘stuck’ because they get instant support when they need it. Home tutors can also question students and ask them to explain the answers they’ve given to check and consolidate understanding.

A tutor can also break down even the most complex homework questions into a series of simpler questions that the student is able to complete. With home tutoring, students complete their homework assignments on-time and always to a very high standard.

#### 3. Students can pre-learn what’s about to be learned in class before a topic begins

Imagine walking into a classroom already knowing the gist of what you’re about to learn. If a student learns a new topic with a home tutor, the classroom environment becomes the place for revision rather than first-time learning. Learning a complicated subject like VCE Chemistry is far more efficient this way. Probably the greatest benefit of pre-learning with a home tutor is that students can then make a great impression among their teachers and peers by grasping ‘new’ concepts extremely quickly in class, which gives them a huge confidence boost in the subject!

Not all schools set enough homework tasks. You can ask your tutor for more homework questions. Unlike most classroom teachers, a home tutor knows your student’s exact strengths and weaknesses in the subject with great detail, and can select homework questions from a wider range of sources to help your student improve on the exact topic areas where they need more practice.

#### 5. Students receive very, very detailed feedback on their written answers with a home tutor

In a VCE Chemistry examination, writing “the solution decolourises from blue to colourless” might earn one mark, whereas “the solution loses some of its colour” will not. Labelling ethanol in a combustion equation as “liquid (l)” might earn one mark, whereas “aqueous (aq)” will not. A classroom teacher marking dozens of tests can easily miss the subtle nuances of language that VCAA examiners are be looking for, or might not have the time to explain exactly why a question was answered incorrectly to each student in a class.

Home tutors can examine, question and correct every answer the student givesno matter whether it’s written or spoken—and provide instant feedback on the student’s responses as they work. Instant feedback is very motivating and time-saving for students.

#### 6. Students get a second voice explaining new concepts

If the class is quite large, or if the teacher has a heavy accent, not all students will understand all of what the teacher is saying. Home tutors can explain the course concepts one-to-one in a quiet, home environment, which is efficient, engaging, and is always done in a way that the student understands.

#### 7. Students get an extra set of textbooks

Home tutors always coach students from different schools. Hiring a home tutor allows you to gain access to a second set of textbooks, past paper examinations and practice materials from that teacher, which your current school might not have access to.

#### 8. Students get meta-study tools from home tutors as well

Home tutors do more than just review content, help with homework assignments and pre-teach upcoming topics. They also provide students with:

• personalised examination revision timetables
• examination tips
• thorough notebook checks
• general study tips
• note-taking strategies (e.g. Cornell)
• and more…

The benefits of home tutoring allow the student to maximise their potential in homework, tests and examinations not only at VCE level, but throughout all the years of university as well. For as long as a student is sitting some kind of examinations, the student will be using above the strategies that a home tutor can provide.

As a VCE Chemistry and Physics teacher, I can testify that students with regular home tutoring are generally happier and more focussed in class, pursue their homework tasks more thoroughly and gain higher scores in tests because they’ve had the one-to-one time required to learn all the subtle nuances in language that examiners are looking for.

## Find a tutor fast in Melbourne’s south-east suburbs.

Leave me a message using the contact form below.

# Best Chemistry Revision Resources

I teach VCE Chemistry at an awesome high-school in Australia. VCE Chemistry can be a difficult subject to learn, and the more help students get from different locations, the better they’ll do in an exam.

Here’s my list of the best Chemistry revision resources on the Internet:

## 1. Richard Thornley IB Chemistry (tutorial videos)

My all-time favourite Chemistry tutor on YouTube. He’s accurate, succinct, and has a great sense of humour. He’s really easy to understand, even when he’s explaining advanced concepts. Great use of customised video gaming to simulate chemical concepts, too. 🙂

## 2. Khan Academy (tutorial videos)

World-class tutorial videos from the legendary Sal Khan. Sal teaches you Chemistry right through to university level, so if you’re still in high-school, you’ll need to select the videos that are right for you. Easy to follow and the website is constantly being updated. Great community of Khan academy users are available in the comments sections to answer your questions 🙂

## 3. CrashCourse Chemistry (tutorial videos)

Fast-paced revision videos that remind you of chemical concepts you’ve already learned. Probably too rapid for learning new content, but they make for very entertaining revision. Excellent graphics & excellent production.

## 4. Chemguide (revision notes)

Classic revision notes for the UK Chemistry syllabus. Covers every topic in depth, and with a really simple website layout. Timeless, comprehensive resource for all students and teachers.

Chemguide Revision Notes

## 5. Compound Interest (posters)

A brand-new Chemistry blog that explores the everyday relevance of chemical compounds. Their food poster series and “Chemistry of Colour” posters have gone viral, and they’ve even been selling Chemistry-themed spice-jar labels! Compound Chem produce high-quality graphics that stimulate more interest in Chemistry.

## 6. Chemisode (tutorial videos)

Jason Goudie guides you through VCE Chemistry with these video tutorials covering Units 1–4. He narrates over Keynote slides, and does practice questions with a camera over a pen & paper. The playlist takes a long time to finish, but it’ll teach you everything you need to know for high school. Designed for VCE Chemistry in Australia.

## 7. Daria Kohls’ Chemistry Dropbox (Revision Cards)

Awesome revision cards for A-level Chemistry. With one card for each Chemistry concept, this treasure trove of revision resources is a bit like VCEasy for A-level 🙂 Get the whole set from Daria’s Dropbox folder using the link below.

## 8. TED-Ed (mini-lessons)

Short, animated films explain Chemical concepts very well. Unfortunately, only about 10% of our high school course has been covered by TED-Ed’s lessons. In a few years’ time, this could become the best Chemistry resource on the web. Search for the topics you need.

TED-Ed Website

## 9. Fuse School (tutorial videos)

Absolutely awesome animated videos that explain chemical concepts. Covers about one-third of our high-school curriculum. Explained really clearly in a beautiful British accent, each video contains a couple of quiz questions.

## 10. Tyler DeWitt (fun tutorial videos)

Tyler DeWitt teaches by telling stories. He anthropomorphises cells and molecules, and gives them feelings as they collide, transform and form products. His classic TED talk (here) is indicative of his unique teaching style. Excellent material for Grades 9-11.

## 11. chemistNATE (tutorial videos)

More great Chemistry videos from a popular teacher on YouTube.

chemistNATE’s Lessons & Worksheets Website

## 12. Brightstorm (tutorial videos)

Brightstorm produces very high-quality Chemistry videos using a whiteboard. Excellent scripting & production, and excellent teaching. Great website, too!

Brightstorm Chemistry Website

## 13. IsaacsTEACH (tutorial videos)

Produces tutorials rather like Khan Academy, except that you can see the teacher on the screen. Very clear explanations.

## 14. Bozeman Science (tutorial videos)

Great video tutorials. Use the search box to find the topics you want to learn about.