Ch. 1

Question 1

What are the 7 Green Chemistry Principles?

Answer 1

1. Plan ahead (to prevent waste)
2. Be efficient (to maximize incorporation of starting materials into finished product)
3. Use less energy (perform rctns at ATP)
4. Be cautious (minimize chemical accidents)
5. Limit toxicity
6. Go renewable
7. Go biodegradable

Question 2

Scientific Method Steps

Answer 2

1. Observation (quantitative/qualitative)
2. Hypothesis (tentative explanation/prediction according to current knowledge)
3. Experiment (systematic, controlled observations/measurements)
4. Law (verbal/mathematical description of what happens. Always same under same conditions)
5. Theory/Model (explain WHY the behaviour occurs. based on reproducible evidence. change if new facts discovered)
6. Back to experiment as needed!

Question 3

Reporting Scientific Results

To ensure integrity in science

Answer 3

1. Results should be reproducible
2. Should be reported with sufficient detail to be reproduced by others
3. Conclusions should be reasonable and unbiased
4. Credit should be given where due
5. Peer review for publication

Question 4

Metric System Values

Answer 4

exa (E): 10¹⁸

peta (P): 10¹⁵

tera (T): 10¹²

giga (G): 10⁹

MEGA (M): 10⁶

KILO (k): 10³

hecto (h): 10²

deka (da): 10¹

DECI (d): 10^-1

CENTI (c): 10^-2

MILLI (m): 10^-3

MICRO (µ): 10^-6

NANO (n): 10^-9

PICO (p): 10^-12

femto (f): 10^-15

atto (a): 10^-18

Question 5

Quantitative Observation

2 types of properties

Answer 5

Intrinsic / Intensive Properties:

• Characteristic of the substance itself, not the quantity
• ex: density, melting point, viscosity

Extrinsic / Extensive Properties:

• Properties that depend on the quantity of substance present
• ex: mass, volume, height, …

Question 6

Celcius to Kelvin Ratio

Answer 6

°C + 273.15 = K

Question 7

Uncertainty on a scale

Answer 7

• Last digit is uncertain but significant
• On an analog scale, the last digit would be guessed by us between the two readable gradations
• 2.382g +/- 0.001g

Question 8

Random (indeterminate) error

Answer 8

• Measurement has equal probability of being high or low
• Usually unavoidable
• Magnitude determined by size of scale divisions
• Direction determined by randomness each time last digit is estimated

Question 9

Systematic (determinate) error

Answer 9

• Occurs in the same direction each time (too high or too low)
• Often results from poor technique or poor experiment design
• Magnitude determined by size of scale divisions or worker’s attention to detail
• Direction determined by calibration of the instrument

Question 10

Accuracy

Answer 10

• The agreement of a particular value with the true or accepted value
• Is the measurement close to the accepted value?
• We look at relative error %

Question 11

Precision

Answer 11

• The degree of agreement among several measurements of the same quantity
• Same result or close each time
• We look at deviation or standard deviation

Question 12

Error Calculations

Answer 12

Relative error: Abs value (Avg experimental value - true value)÷true value

% error: avg exp val - true value / true value x100%

• Often as a percentage so multiply by 100%
• Can be ppositive or negative

Question 13

Standard Deviation Formula

Answer 13

sqr rt ((deviation from avg 1)²+(deviation from avg 2)²+(deviation 3)²+…÷(number of measurements - 1))

Question 14

How to calculate standard deviation

Answer 14

1.

Question 15

20 first elements

Answer 15

1. Hydrogen
2. Helium
3. Lithium
4. Beryllium
5. Boron
6. Carbon
7. Nitrogen
8. Oxygen
9. Fluorine
10. Neon
11. Sodium
12. Magnesium
13. Aluminum
14. Silicon
15. Phosphorus
16. Sulfur
17. Chlorine
18. Argon
19. Potassium
20. Calcium

Question 16

Avogadro’s Number

Answer 16

6.022x10²³