Chemistry Chapter 2

What are the 4 Major Stages in the Scientific Method IN ORDER

1. Observing
2. Formulating Hypothesis
3. Testing
4. Theorizing

What is the difference between accuracy and precision?

Don't know the standard? Can't tell you if it's accurate!

EX: 10.224 g, 10.259 g, 10.235 g

Not precise and cannot tell the accuracy is. Low precision.

What is the equation for an inverse proportion?

P (Pressure) x V (Volume) = K (constant)

How do you use dimensional analysis to arrive at the correct units?

Put labels in the right place to cancel out.

EX: km/hr ...100m/1km - 1km/60 min - 1min/60sec = m and sec are the only labels left

What are the rules for significant zeros? - Which has non-significant zeros?

0.0040 m
400.0 m
404.0 m
40.00 m

0.0040 m - the zeroes before are place holders

Within DIRECT and INVERSE variables. what happens if the other increases?

DIRECT: one increases, the other does too

INVERSE: one increases, the other decreases

What is the correct rule for multiplication and division with significant figures?

Always use the least number in the measurements.

EX: 12m x 4.165m = (only two sig figs.)

NAME THE QUANTITY MEASURED: J

Joules - energy

NAME THE QUANTITY MEASURED: s

Seconds - time

NAME THE QUANTITY MEASURED: g/mL

Grams per milliLiter - density

NAME THE QUANTITY MEASURED: K

Kelvin - temperature

NAME THE QUANTITY MEASURED: L

Liter - volume

NAME THE QUANTITY MEASURED: m

Meters - length

NAME THE QUANTITY MEASURED: m^2

Meters (squared) - area

NAME THE QUANTITY MEASURED: m^3

Meters (cubed) - volume

NAME THE QUANTITY MEASURED: kg

Kilograms - mass

What is the difference between QUANTITATIVE and QUALITATIVE

QUANTITATIVE is using NUMBERS
EX: 25g of paper clips
QUALITATIVE is using WORDS
EX: the sky is blue

QUANTITY

Something that has magnitude, size, or amount

CONVERSION FACTOR

a ratio derived from the equality between two different units

DERIVED UNITS

combinations of SI base units

WRITE IN SCIENTIFIC NOTATION

50,400 m

5.04 x 10^4

What is the rule with sig. figs?

If it is 5, look at the number before it. Even LEAVE IT! Odd ROUND UP.

EX: 0.0625 = 0.062

DO A CORRECT MEASUREMENT CONVERSION

635 g to kg

635 g x 100 g/ 1kg = 0.635kg

How does THEORY differ from HYPOTHESIS?

THEORY: broad generalization of mass and phenomena

HYPOTHESIS: testable statement

How does WEIGHT differ from MASS?

WEIGHT is a force due to gravity

MASS is the amount of material that makes up an object

How are models used in science?

Give a physical explanation to phenomena

PRACTICING PERCENT ERROR

Experimental: 6.40

Accepted 6.36

% error= exp-acc/acc x 100

6.40 - 6.36/6.36 x 100 = 0.6289

0.6289 rounds to 0.6%

WHAT IS THE VOLUME IN LITERS OF A CUBE

One side = 2.25 cm

2.25 x 2.25 x 2.25 = 11.4 cm^3

11.4 cm^3 x 1L/1000cm^3 = 0.0114 L

WHAT IS THE SUM OF 1.026 g and 0.07565?

1.026 + 0.07565 = 1.10165

ROUND ONLY TO THE THIRD DECIMAL due to the number 1.026

1.102