what's happening that's causing you to fail chemistry 3 times? Something in your life? Are you not studying? Do you know your resources?
What I'm about to write goes for ALL your classes not just chemistry..
First thing you need to accept is that no one just knows this material. You included. You can't just walk into a test (especially not in chemistry), take the test and pass. You have to study. You have to take the responsibility to learn the material!
The next thing you need to understand is chemistry (and math and physics and etc).. .especially chemistry.. is like a foreign language. There's structure, there's vocabulary, there are "common" ways we communicate and generic problem solving process that you need to learn and practice applying. You can't learn a foreign language without some memorization, and PRACTICE. right? That's the only way you'll be fluent in it. And that takes years "speaking" it. You have to be immersed in it.
Back in my college days, I TA'd general and organic chemistry while working on my graduate ChE degree. The following are the best practices of the best students that I observed and how I approached all my classes. I highly recommend you follow my advice here
(1) Obtain the book ahead of the first day of class. READ AND STAY AHEAD of the lectures. Why is this important? Because when you read ahead, whether you understand everything or not.. you will at LEAST be familiar with the concepts. That will make lectures understandable. You'll hear what the teacher is saying instead of hearing gibberish. If you're taking Gen Chem in the fall, get a copy of the book in say.. JUNE (check with the instructor for that class and ask them what book you'll be using. They might even loan you a copy).
(2) TEACH YOURSELF by working out the problems at the end of the chapter BEFORE your class ever gets there. Yes, you might struggle a bit. Yes you might have questions.. but... doing this will make your understanding better and will make the examples your teacher gives you... easier to understand. You might actually say.. "ah ha" or "yes" or
"now I get it"... during class. And when you get to college, I guarantee you.. NO teacher is going to crack your head open and pour knowledge into it. You are expected to learn on your own. Your teacher is there as a guide.. not as a brain surgeon.
(3) WORK THE PROBLEMS... You'll get assignments, you have to work out all the problems you get. The best of the best students work out ALL the assignment problems + ALL the rest of the problems. You must do the assignments. If you can't do the rest of the problems due to time, at least glance at them and formulate a solution in your head. Solving problems is > 50% of general chemistry class. The only way to get good at this is by practicing. The more you practice, the better you'll be and the faster you'll be and the better your grade will be.
(4) KNOW YOUR RESOURCES. Know where to turn to for help. Many students never learn this and fail because of it. Possible resources.. (a) Your teacher (ask questions). (b) TA's (c) The internet. you have a universe of information at your fingertips. Every problem imaginable is already solved and posted on the internet. There is no reason you can't find a similar solution and apply the method to your homework problems! In my days, we had to walk to the campus library to look up obscure information.. it's all right there for you on your laptop... and all you need to do to find it... is use google. (d) chemistry forums (like this one or like yahoo answers, etc). Many of us in the field donate countless hours of our time answering questions here to students having trouble. Yes, some answers are better and you get to sort them out (e) Form study groups.. more on that in a second. (f) find past exams, past homework assignments, etc, from your teacher and online. Study those problems. (g) I would avoid tutors.. they are expensive and not all are good. but IF you absolutely need to, hire a high school chemistry teacher as a tutor. Not a fellow student!
(5) FORM STUDY GROUPS. I highly recommend this. Group up with 3 or 4 others in the class and meet every Tuesday and Thursday after school at Starbucks. If you think it's too late to start now, you're wrong. I guarantee you, some of the students in your class are doing this already. Find them and join them... or start your own group. The idea is when you work together you have 4 or 5 minds all solving the same problems from different perspectives. It makes the work faster and better. And when you rehash this as a group, you tend to understand it better. The more times you go over it, the better you'll get. If you can teach the concepts to other members to other members of the group, it will make YOU better!
(6) LEARN THE TRICKS AND TECHNIQUES. I can't tell you how important this is. The key to solving chemistry problems is NOT memorization of solutions. It is learning techniques and learning how to apply those techniques to a variety of different situations. One of the most powerful techniques you'll see in general chemistry is "factor label method" which is the backbone of ALL the math in general chemistry. If you learn that technique and how to apply it, you can skim through just about any chemistry problem and solve it FAST and accurately. Another technique is "the six steps to solving stoichiometry problems" You memorize the STEPS. Not solutions to any particular problems. Another technique is "the 7 steps to balancing redox reactions". Again, you memorize the STEPS... not the solution to a problem. You practice applying those steps to different problems and you'll ace whatever your teacher throws at you. There are about a dozen "techniques" you'll need to learn for general chemistry. LOOK for them in your lectures and books. Think about the steps you go through when solving problems.
(7) BE ON TIME. if you turn in an assignment 1 day late, you'll lose points. Those points are gone forever and lost foolishly. You work hard for those points. Don't rip yourself off by being late. In fact, I recommend having your assignments done at least 1 day early if possible. Take a break from them, then go back and read through your work again make corrections if necessary. This repeated editing will make your work outstanding and make YOU understand the method better and help you to recognize how to apply it to other problems... which will make you faster for homework and faster on exams.
DEMONSTRATE YOUR EFFORT. Participate in class. Meet with your instructors or TA's regularly. This demonstrates you're trying. If your grade is borderline and you're showing you're trying hard, you might get the better grade.
Those 8 items are "best practices" I highly recommend you take to heart and apply to all your studies. Specifically for chemistry, I highly recommend learning these three things before first day of class
(1) molar mass vs atomic mass vs molecular mass vs formula unit mass. If you don't understand these statements, then you don't know this material well enough. "atomic mass is the mass of 1 atom. Molecular mass is the mass of 1 molecule. Formula unit mass is the mass of 1 repeating unit of an ionic compound. Molar mass is the mass of 1 mole of whatever you're referring to (atoms, molecules, formula units, Earth like planets, etc). 1 mole of entities = 6.022x10^23 entities. 1 AMU / 1 atom = 1 gram / 1 mole of atoms. mass / atom = atomic mass. mass / mole of __ = molar mass."
(2) "factor label method"... (aka dimensional analysis to chem students). If you don't know the following principles and best practices, you need to spend time learning DA.
(i) "the identity principle" anything x 1 = that same thing
(ii) "the canceling principle" units on top and bottom of a fraction cancel
(iii) "the unit factor principle" given a = b... a/b = b/a = 1... a/b and b/a are "unit factors"
(iv) "the conversion principle" we combine (i), (ii) and (iii) to convert units but not fundamental value
(v) "the power rule" any unit factor raised to any power = 1
and best practices
(i) sort through each problem.. identify what you want to convert FROM, TO
and all the UNIT FACTORS you're given.
(ii) start with the FROM on the left and convert to the right
(iii) convert the numerator first, then the denominator.. this isn't required but it
builds consistency and makes you better stronger and faster.
(iv) make sure any unit factors you look up have at least as many sig figs as the
FROM and preferably 1 extra. This forces the imprecision in the result to be due
to the FROM and not your choice of unit factors
(v) setup the conversion equation FIRST.. then verify it's setup correctly. check the following
(a) everything cancels properly
(b) the unit factors are correct... .(2.54cm / 1in).. NOT... (2.54in / 1cm).. see the diff?
(vi) run the calcs all at once. Don't break down the equation. repeat if time permits
(3) sig figs. you need to know (i) what is and isn't a sig fig, (ii) the three operations of sig figs.. mult/div & add/sub & logs, (iii) order of operations.
you need to be able to see a problem like this
"a silver coin of mass 5.85g was dissolved in HNO3. NaCl was added in XS and 7.20g of silver
chloride was ppt'd out of solution. What is the % silver in the coin?"
and understand this solution
7.20g AgCl 107.9g Ag
-------------- x -------------- x 100% = 92.7% Ag in the coin
5.85g coin 143.3g AgCl
and you should be able to notice the following
(1) I started with what I was given on the left and converted to % Ag in the coin (by mass)
on the right
(2) the given values were 7.20 (3 sig figs) and 5.85 (3 sig figs). I looked up the molar mass
(not atomic mass) of Ag and molar mass of AgCl. Those values have 4 sig figs (1 more
that the 3 in my 2 "givens". The result is limited to 3 sig figs
(3) my unit factor is mass fraction Ag in AgCl
(4) how the units cancel g AgCl / g AgCl cancel right?
anyway... that's my recommendation for today. If you need motivation to pass the class. Think big picture
imagine yourself spending 8 hrs a day running a register at Walmart. Think of the people you'll interact with. Think of the mundane nature of the job. Think about your pay. $8.25/hr * 40hrs/week * 52weeks/yr * 1yr/12mo * $0.70 take home/$ earned = $1000 / month. That's your spending power. Let's say you marry someone else who works at Walmart and the two of you earn $2000/month. The rent on your trailer is say $750/month. Your electric bill is $150/mo. Your water bill is $50/mo. Your phone bill is $100/month. Your TV/internet bill is $50/month. Let's say the two of you each own a car. One of those beat up cars with different colored doors and bald tires. Paint is peeling. Seats are torn. Etc. You have insurance but just the basic. $150/month ins. Gas is $200/mon (both cars included). That leaves you with a whopping $550 per month for food, clothes, entertainment, health, etc. $127/week the two of you split on food, clothes, beer, etc. < $20 per day. How can you possibly survive? How will you ever improve your life? What happens if you have a baby and need childcare ($1500/month).
Now imagine you get through college. Four years of it. Not your current plan of 7 years. 4 yrs * 9months/yr * 30 days/mo - 116 days for holidays = 964 days. That's it. 964 days total. And lets say you get a bachelors degree in chemical engineering and go out into the world and start working. Your first job pays $70k/yr. Years 2-5, you get a 3% raise + 10% bonus + 9% contribution to your retirement fund each year. Year 3 you're given a promotion with a 10% raise. Year 5, the company pays for you to get an MBA ($120k degree fyi). Year 7 you're promoted to a middle management role with a salary of $120k/yr + 9% IRA + 20% cash bonus + 30% stock options. You contribute 5% of your salary to your IRA. Your take home is (120,000 * 1.20* 0.64 / 12) = $7,680/mo. Your IRA has grown to $100k. You're 29 years old. Along the way, you marry someone with identical earnings. Your combined takehome pay is $15,360 / mo. The two of you buy a $750,000k house with a 15yr mortgage. You put 20% down in cash that you've saved. Your house payments are $5400/mo (including property tax). You have 3 cars (a BMW X-7 SUV, a BMW I-8, and a Tesla model "S") with a monthly car payment of $3600. you utilities total $1000/mo. Your insurance, gas and maintenance = $750/mo. Leaving you with $6k / month for groceries, clothes, vacations in the Bahamas, kids. savings, etc. When you're 32, both of you have stock options that vest and cash them out for $50k after taxes. You're earning 10% more and you have $500k in your retirement funds. When you're both 50, you retire with $10MM in your IRA's, $5MM in liquid assets. Your house is paid off and is now worth $1.2MM. You buy new cars every couple of years... vacation where-ever 4 times per year and you start planning on college for the 2 kids you're raising. etc.
Which life do you want? An eternity of ringing up shopping carts packed with Walmart stuff, living in a trailer, driving a broken down multi colored rusted out car, eating ramen noodles and crusty McD burgers.... or.... living in that mansion, driving luxury cars, wearing nice clothes, eating healthy food and going out whenever you please, vacations in the Bahama's + retiring early. Not to mention, which spouse do you want (Walmart or professional)? What life would be better for your kids.
It's your choice how to spend those 964 days. I think you need to figure out what you're doing wrong and fix it. But that's just my opinion right?