1. b) Compound – a substance of definite composition of elements. It can be decomposed into two or more simpler substances by simple chemical changes but not by physical means. Example: SMORES 1 smore contains 2 graham crackers, 1 marshmallow, and 3 chocolates 6 smores contain:graham crackers marshmallows chocolates Ratio of crackers to marshmallows to chocolates = 2:1:3 1 12 6 18

2. 1 smore contains 2 graham crackers, 1 marshmallow, and 3 chocolates Ratio of crackers to marshmallows to chocolates = 2:1:3 2 49 graham crackers 23 marshmallows 69 chocolates 23 smores!

3. Chapter 2 Measurements and Units 1. Metric System mass – gram, g (1 g = 0.0022 pounds) length – meter, m (1 m = 39.37 inches) volume – liter, L (1 L = 1.06 Quarts) temperature – Celcius or centigrade, o C Freezing point of water = 0 o C Boiling point of water = 100 o C Energy – calorie, cal 1 cal = energy required to change 1 g of water 1 o C Time – second, s

4. 2. Prefix pico p 10 -12 = 0.000000000001(one-trillionth)

5. centimeter (cm) 1cm = 0.01 m = 1/100 m millimeter (mm) 1 mm = 0.001 m = 1/1000 m milliliter (mL) = 0.001 L = 1/1000 L kilometer (km) 1 km = 1000 m kilogram (kg) 1 kg = 1000 g kilocalorie (kcal) 1 kcal = 1000 cal megabite (MB) 1MB = 1,000,000 bites gigabite (GB) 1 GB = 1,000,000,000 bites

6. 1 c.c.

7. 3. Accuracy and Precision Accuracy - the correctness of a measurement Precision – reproducibility of measurements.

8. 4. Significant figures

10. 1.345 significant figures 0.2300 significant figures 0.00230 23.400500

11. 5. Exponential notation (scientific notation) 23000000 2 significant figures 2.300 x 10 7 ? significant figures 0.000000230 = 2.30 x 10 -7 ? 2.300 x 10 -7 ? = 2.3 x 10 7

12. Perfect units, exact numbers and inexact numbers An exact number is a number whose value has no uncertainty associated with it – a number that arises when you count items or when you define a unit. 1 ft = 12 in 1 hr = 60 min 1 cm = 1/10 m ½, ¼, etc. Perfect units Exact numbers 1 kg = 2.205 lb Inexact number Infinite significant figures. Infinite significant figures. The value of an inexact number has a degree of uncertainty. All measurements are inexact

13. 3.8 3.75

14. 6. Significant figure in arithmetic a) addition and subtraction 2.34 + 30.6081 + 30.6081 2.34 32.9481 32.95 b) Multiplication and division 1.32 x 4.011 = 5.29452 = 5.29 3 significant figures

15. 6.3 x 0.000834 = 0.0053 2 significant figures 7. Conversion of units

16. It is experimentally determined that 1 inch equals 2.54 centimeters, or 1 centimeter equals 0.394 inch.

17. Example 1 Convert 2.00 inches to centimeters. Example 2 Convert 9.05 cm to inches. Factor-Label Method

18. Example 3 6.82 cm = ? feet

19. Example 4 How many milligrams are there in 4.00 pounds?

20. 8. Density Density = mass/volume (g/mL) Figure 2.7 (a) The penny is less dense than the mercury it floats on. (b) Liquids that do not dissolve in one another and that have different densities float on one another, forming layers. a) b)

21. Example 1 2.0 g of metal occupies 0.40 mL. What is the density? Example 2 Density = 2.0 pounds/quart = ? g/mL

22. Specific Gravity – ratio of the density of a substance to that of water. Density of lead = 11.3 g/mL specific gravity of lead = 11.3 Example: density of water = 1.00 g /mL no unit

23. 9. Temperature Figure 1.4 Change of 180 o F = change of 100 o C oFoF oCoC 0o0o 100 o 32 o 212 o 180 o 100 o

24. Change of 180 o F = change of 100 o C Change of 1 o F = change of 100 180 oCoC = change of 5 9 oCoC Change of 1 o C == change of 9 5 oFoF Example: 50 o F = ? o C oFoF oCoC 0o0o 32 o 33 o 34 o 1o1o

25. oFoF oCoC 0o0o 32 o 212 o 100 o

26. Absolute Temperature – Kelvin, K K = 273 + o C examples

28. 10. Heat energy and specific heat Unit of heat energy – calorie (cal) 1 cal = heat needed to raise 1 g of water 1 o C 1 kcal = 1000 cal 1 cal = 4.184 Joules (J) SI system Specific heat (SH) of a substance SH = amount of heat needed to raise 1 g of that substance 1 o C SH = heat absorbed Mass x change of T = cal m x  T cal = SH x m x  T

29. SH of water = 1.0 ( cal g. o C ) Example 1 : How much heat is needed to raise 30 g water from 20 o C to 30 o C?

30. Example 2 122 cal of heat is added to 20 g of methanol at 15 o C. What is the final temperature? SH of methanol = 0.61 cal/g. o C

31. Example 3 What quantity of heat is required to raise the temperature of 50 mL of ethanol from 22.0 o C to 25.0 o C? The density of ethanol at this temperature is 0.80g/mL. The specific heat of ethanol is 0.59 cal/g o C.

32. Substance in blood Typical range Calcium 8.5 – 10.5 mg/dL Sodium 3.10 – 3.33 mg/mL Potassium 137 - 200 mg/L Cholesterol105 – 200 mg/dL Fasting glucose 70 – 110 mg/dL Total protein 6.0 – 8.0 g/dL