Chemistry Video 2

Question 1

Accuracy

Answer 1

How close a measurement is to the true value of something

Question 2

Precision

Answer 2

Closeness of a set of data points to each other. More digits = more precise

Question 3

SI unit length

Answer 3

Meters; millimeters, micrometer, nanometer, kilometers.

Question 4

SI unit volume

Answer 4

Liters

Question 5

SI unit mass

Answer 5

Kilograms

Question 6

SI unit temperature

Answer 6

Kelvin. 1 Kelvin is the same magnitude as 1 Celsius. 273 K = 0 C. C = K - 273. Absolute temperature scale

Question 7

SI unit time

Answer 7

Seconds

Question 8

Derived units

Answer 8

Combine more than 1 unit together. Ex. Area (m^2), Velocity (m/2), volume (m^3)

Question 9

Significant figure

Answer 9

Digits that contribute to the precision of a value

Question 10

4 rules of significant figures

Answer 10

1. Any non-zero digit is significant
2. Zeroes in between non-zeroes are significant
3. Leading zeroes are not significant
4. Trailing zeroes are significant if they are decimal zeroes

Question 11

Significant figures in addition and subtraction

Answer 11

Answer is rounded to the decimal place reflective of the value with the fewest decimal places

Question 12

Significant figures in multiplication and division

Answer 12

Answer is rounded to the sig fig reflective of the value with the fewest sig figs

Question 13

Requirements for measurements

Answer 13

Quantitative/convey magnitude, must contain a unit, must indicate some uncertainty

Question 14

Dimensional analysis

Answer 14

Change the units of a value by multiplying by “1”. Multiplying by 1 does not change the magnitude of the value

Question 15

Density

Answer 15

Mass per unit volume, derived unit. Units: g/mL, g/cm^3, kg/L, kg/m^3

Question 16

Density depending on phase of matter

Answer 16

Solids have high density, liquids have high density, gases have low density