# Chemistry Tips

I tutored a student in regular, high school Chemistry AB last year, and I put together a list of important points to remember. Here is what I wrote. Some of the tips are only important for beginner’s chemistry and are not applicable in higher levels. However, I assume that if you are in a higher level of chemistry, you are familiar with the occasion to use that tip (such as converting mass).

1. A mole is a unit of quantity in the same way a dozen is a unit of quantity.
2. When starting a problem, always write the given numbers and information.
3. Set up given in dimensional analysis and write the given unit diagonally.
4. REMEMBER UNITS.
5. If the units don’t cross out, there is either a problem OR it is the unit you are looking for.
6. Always exchange mass and # of particles with moles. ( Mass (g) -> Moles (mol) <- # of particles )
7. Division help: Cowboy rides horse (Cowboy/Horse). At night, the cowboy sleeps in the house, and the horse sleeps outside (picture long division with the cowboy beneath the sign)
8. To calculate molar mass on a calculator, visually move the subscripts behind the element and replace the element letter(s) with their own molar mass. Multiply and add as needed. [Ex: C2H3O2 becomes 2(12.01)+3(1.01)+2(16)]
9. If mass is associated with mole, use molar mass.

Tips for Quest (from UTexas)
1. Use "E" notation in place of scientific notation [*10^(exponent)] (Also, do not call this "e to the…" because there is an actual "e", the natural number. Refer to this as "E exponent"
2. Likewise, do not mix up e^(exponent) and E(exponent)
3. Writing the units is not necessary, but MAKE SURE THE ENDING UNITS ARE WHAT QUEST WANTS.
5. Webelements.com is your friend

Setting up a problem
1. Write the number down, with its units, and draw the parentheses or fraction lines for dimensional analysis
2. Write the aforementioned unit in the diagonal space
3. Is this unit related to moles? (mass, # of particles) If so, remember to write the molar mass next to the g or 6.02e23 next to the f.u./atoms/molecules/r.p.
4. Is the unit preceded by a prefix? If so, remember to calculate for the base unit (EX: if kg, divide 10^3 g by 10^0 kg)
5. Once all numbers and units are placed, cross out divided units and calculate. Multiply all numbers on the same side of the horizontal line, then divide the top numbers by the bottom numbers.
6. Check if the end unit matches what the problem wants.