1 0900 final review. 2 lab stuff – what is it? 3
Post on 19-Dec-2015
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2
Lab stuff – what is it?
1. 9501002. 95013. 950.14. 95.015. 9.5016. 0.95017. 0.0000009501
Counting Sig Figs & Proper Scientific Notation
6
Metric System
• SI Units – what are they??
• Base unit
• Conversions – – Dimensional Analysis– Move the decimal– 556.02g = __________ hg– .00911m = __________ mm
8
Mass Measurements
• What kind is this?• Are measurements
direct or indirect?• What is the estimated
digit?
18
Pipets• What kinds are
these?• How do you
know what the volume is?
• How do you know what the increments are?
25
Ratios & Proportions
• Ratios can be written 3 different ways
A ratio of 3 boys to 5 girls can look like:
• 3 to 53
• 3 : 5
• 3/5
• Is the order important??
29
Probability:
• If you have a deck
Of 52 cards, what is
The probability of
Selecting a 1 of hearts?
What is the sample space?
37
Solutions
25.0 g of sugar is added to 125 mL of hot coffee. What is the %concentration?
1.5g of powdered Tang to water for a total solution of 50mL. What is the % concentration?
47
Which ball has the greatest Potential Energy? Why?Which ball would have the least Potential Energy? Why?
48
Which ball would have the least Potential Energy? Why? Which ball would have the least Potential Energy? Why?
49
Which ball would have the greatest Kinetic Energy? Why?Which ball would have the least Kinetic Energy? Why?
50
Which ball would have the greatest Kinetic Energy? Why?Which ball would have the least Kinetic Energy? Why?
Significant Figures - Why do we use them? How to count?
58
1. Always count nonzero digitsExample: 21 has two significant figures, while 8.926 has four
2. Never count leading (placeholder) zerosExample: 021 and 0.021 both have two significant figures
3. Captive zeros - Always count zeros which fall somewhere between two nonzero digitsExample: 20.8 has three significant figures, while 0.00104009 has six
4. Count trailing zeros if and only if the number contains a decimal pointExample: 210 and 210000 both have two significant figures, while 210. has three and 210.00 has five
59
How many of the following numbers have 4 significant figures?
3.003 16.00 0.004 1.24 x 104 0.001204
a) 4b) 3c) 5d) 2e) 1
How many significant figures are in the number 0.00246?
a) fourb) threec) fived) twoe) six
62
Calculate the following to the correct number of significant figures.
1.00 + 12.3 = _____
a) 11b) 13.3c) 11.299d) 13e) 11.2
Calculate the following to the correct number of significant figures.
10.23 + 4.355 = _____
a) 14.585b) 14.58c) 15d) 14.59e) 14.6
63
Calculate the following to the correct number of significant figures.
212.1 - 89.342 = _____
a) 122.76b) 122.8c) 122.758d) 123e) 122.7
65
Calculate the following to the correct number of significant figures.
2.301 / 0.0120 = _____
a) 191.7b) 191.75c) 191.8d) 191e) 192
Calculate the following to the correct number of significant figures.
2.34 / 0.12 = _____
a) 19.5b) 19c) 0.28d) 0.281
e) 2.0 x 101
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Calculate the following to the correct number of significant figures.
81.25 x 0.0014 = _____
a) 0.114b) 0.1c) 0.1137d) 0.1138e) 0.11
Rounding Sig Figs
67
Round to 2 sig figs
Round to 3 sig figs
1.235
0.0025653
205.203
3463200
230.940
0.002030
68
A crucible is known to weigh 24.332 g. Three students in the class determine the weight of the crucible by repeated weighings on a balance. Using the following information, which student has done the most precise determination?
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5A 24.8 24.9 24.8 24.9 24.8B 24.8 24.0 24.2 24.1 24.3C 24.5 24.1 24.5 24.1 24.3
a) Student C has done the most precise work.b) Student A has done the most precise work.c) Student B has done the most precise work.
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Consider the data obtained for the length of an object as measured by three students. The length is known to be 14.54 cm. Which of the conclusions summarizes the data?
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5A 14.8 14.1 14.5 14.6 14.2B 14.5 14.6 14.6 14.5 14.7C 14.3 14.4 14.4 14.3 14.3
a) Student A has done the most precise work and student C the most accurate.b) Student B has done the most precise work and student C the most accurate.c) Student B has done the most precise work and student A the most accurate.d) Student C has done the most precise work and student A the most accurate.e) Student C has done the most precise work and student B the most accurate.