Cheatography

# chem final is stupid Cheat Sheet (DRAFT) by ChemIsForSheeit

stuf for chem final exam aka stupid

This is a draft cheat sheet. It is a work in progress and is not finished yet.

### Sig Fig Rules

 To determine the number of signif­­icant figures in a number use the following 3 rules: 1.Non-zero digits are always signif­­icant 2.Any zeros between two signif­­icant digits are signif­­icant 3.A final zero or trailing zeros in the decimal portion ONLY are signif­­icant Example: .500 or .632000 the zeros are signif­­icant .006 or .000968 the zeros are NOT signif­­icant For addition and subtra­­ction use the following rules: 1.Count the number of signif­­icant figures in the decimal portion ONLY of each number in the problem 2.Add or subtract in the normal fashion 3.Your final answer may have no more signif­­icant figures to the right of the decimal than the LEAST number of signif­­icant figures in any number in the problem. For multip­­li­c­ation and division use the following rule: 1.The LEAST number of signif­­icant figures in any number of the problem determines the number of signif­­icant figures in the answer. (You are now looking at the entire number, not just the decimal portion) This means you have to be able to recognize signif­­icant figures in order to use this rule Example: 5.26 has 3 signif­­icant figures 6.1 has 2 signif­­icant figures

### No think math method for conver­sions

 #unit1 x #unit (­con­­verting to) / #unit1 #=number cancel like units then multiply and divide then you get your answer with new units

### Ideal Gas Law

 PV/nT=­nRT/nT P=atm V=L liters? n=# of mols T=Kelvin R= 0.0821 atm x L / mol x K ---Always divide the numbers underneath

### Abbrev­iations

 Atmosp­­he­r­e-atm Bar-Bar millimeter of mercur­­y-mmHg Pascal-pa Pounds per square inch-psi Torr-torr

### electron config­uration

 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 6f 7s 7p 7d 7f s=2 p=6 d=10 f=14