1. the ideal gas

2. pV = nRT pressureVolume number of moles Temperature

3. pV = nRT For pV=nRT to work, temperature must be absolute. For an absolute temperature, T=0 means zero energy. Kelvin, K is an absolute temperature. K = o C +273.15

4. What is 100 o C in K to the nearest whole number? What is 100 o C in K to one significant figure? What is 73 K in o C to the nearest whole number? What is 73 K in o C to one significant figure? K = o C +273.15

5. pressure is caused by gas molecules hitting the wall of the container. Volume is size of container. n is the number of moles of gas molecules. R= 8.3 J mol -1 o C -1 Temperature measures the kinetic energy of the gas molecules. pV = nRT

6. p  n Keeping V and T constant: if we double n, we double p. if we triple n, we triple p. if we halve n, we halve p.

7. p  T Keeping V and n constant: if we double T, we double p. if we triple T, we triple p. if we halve T, we halve p.

8. p  V -1 Keeping T and n constant: if we halve V, we double p. if we triple V, we reduce p by a third. if we double V, we halve p. we say p and V are inversely proportional n = constant

9. p  V -1 p  n p  T p  V -1 n T pV  nT pV = nRT deducing the ideal gas law based n the previous proportionality relations

10. pV = nRT If we keep T and V constant, if one doubles n what happens to p? If we keep n and T constant, if one doubles V what happens to p? If we keep n and p constant, if one doubles T what happens to V? If we keep p and V constant, if one doubles n what happens to T? p doubles, n doubles but V stays constant, what happens to T? p triples, V halves and n doubles, what happens to T?

11. proportionality relations

12. c = 2  r c  r p  n V,T constant pV = nRT directly proportional

13. h  w -1 h h w w Area constant p  V -1 n,T constant pV = nRT indirectly (inversely) proportional A = hw

14. other proportionality relations exist. KE = ½ m v 2 if velocity doubles, what happens to KE? if velocity triples, what happens to KE? if velocity halves, what happens to KE? KE is proportional to velocity squared KE  v 2

15. if KE quadruples, what happens to v? if KE doubles, what happens to v? if KE halves, what happens to v? KE= ½ m v 2 v2 =v2 = 2 KE _______ m v = 2 KE _______ m velocity is proportional to square root of KE. v  KE

16. Where applicable, please state the proportionality relation between the following pairs of quantities. If no proportionality relation exists, please state so. State also, where possible, the proportionality constants.

17. V= h x w x d d  w V  w 2 x h V  m m is constant V is constant h  1/w 2 Mr. Fantastic

18. 7.2 (± 0.3) x 10 9 the digit 7 is the first significant figure. the exponent is 9. The most important part of a number is the exponent. The second most important part of a number is its first significant figure. The third most important part of a number is the error bar. 0.3 is the error bar.

19. sphere 4  Volume = _____ r 3 3 proportion- ality relation is a cubed relation proportionailty constant is 4  /3 ≈ 4. The most important part of a chemistry equation is the proportionality relation. The second most important part of a chemistry equation is its proportionality constant.

20. What are the most important parts of the equations below? Please use the proportionality sign in your answers. pV=nRT KE=½ mv 2