Chem 103 Ch 1
round each number to three sig figs 0.036549 1044.987 4.0007
0.0365 1040 4.00
1 degrees C
1 kelvin (K)
0.07 0.010 0.550, 90.0 7.010, 0.05002 725.00
1 sig 2 sig 3 sig 4 sig 5 sig
sig fig rules
1. All non-zero integers are always significant; ex. 2.45 cm =3 sig figs (all digits are significant bc they are not 0's) 2. Zeros in the middle of a number are significant; ex. 8074=4 sig figs 3. Zeros at the beginning of a number are not significant; ex. .0067=2 sig figs 4. Trailing zeros (zeros at the end of a number) Are significant if AFTER the decimal point; ex. 55.0=3 sig figs Are NOT significant in numbers without decimal points; ex. 1000=1 sig fig 5. Exact values have infinite number of sig figs Conversion factors (exactly 2.54cm =1 inch; previously established as an exact, defined quantity) Counting objects (there are exactly 12 eggs in the egg carton; nothing uncertain about this)
12.8L/1cm to mL/m
1.28x10^6mL/m
1043= 0.00077= 673.5= 0.034=
1.43x10^3 7.7x10^-4 6.735x10^2 3.4x10^-2
density of Ti is 4.50g/cm^3. What is the volume of 7.20 g of Ti?
1.60cm^3Ti
24.2mi/1gal to km/L
10.2874
1 picometer (pm)
10^-12 m
1 centimeter (cm)
10^-2 m
1 millimole (mmol)
10^-3 mol
1 microliter (uL)
10^-6 L
1 nanogram (ng)
10^-9 g
1 kilometer (km)
10^3 m
1 megahertz (MHz)
10^6 Hz
1 2 meters to centimeters
1200.0 cm
12+1.2 =how many sig figs
13.2 but 2 sig figs so 13
practice sig figs 105+30.1 = 88/22 = 10.5 + 2.03 -4.72 = (5.00x10^2) x 0.001 = (6.0-5.5)(46056)/228 =
135 3 sig figs 4.0 2 sig figs 7.81 2 sig figs 0.5 1 sig fig 100 1 sig fig
1.72x10^3 = 9.07x10^-2=
1720 0.0907
.296L/1 min to uL/h
17760000uL/h
873cm/1s to in/min
20622.047 in/min
round each number to two sig figs 233.356 0.002353 1.005
230 0.0024 1.0
convert 298K to C
24.85 degrees C
mass is 19.90g, volume is 5.66 mL. what is the density
3.52g/mL
86 F to C
30 degrees C
5.47cm/s to m/min
328.2 m/min
convert 260 F to Kelvin
399.816 K
determine the number of sig figs 0.07016 0.00013 8.04 x 10^-3 20.00 5,000,000 2,090 2,090.
4 2 3 4 1 3 4
a 9 degree F temp change equals a temp change of
5 degrees C and 5 K
10 C to F
50 degrees F
density is .7899g/mL, mass is 39.7g. what is volume
50.259mL
6.104x10^2= 9.5x10^-3= 4.52x10^3= 8.11x10^-2
610.4 0.0095 4520 0.0811
convert 749 K to F
888.53 F
conversion between C and F
C=(F-32)x5/9 F=9/5(C)+32
convert 37C to K
K=C+273.15 K=310.15
kelvin
SI unit of temperature, known as the absolute temperature scale, where the lowest temperature possible is 0 K
A piece of metal ore weighs 8.25 g. When you place it into a graduated cylinder containing water, the liquid level rises from 21.25 mL to 26.47 mL. What is the density of the ore?
V=5.22 mL D=1.58g/mL
compound
a molecule made of atoms from different elements; written using chemical formulas
chemical property
a property of a substance that can only be measured by changing a substance's chemical identity; reacting it to form a substance
physcial property
a property of sunstance that can only be observed without changing the chemical composition of the substance
element
a substance of only one type of atom, can be multiple atoms; written using chemical symbols
uncertainty in measurements
all measurements contain uncertainty
law of constant composition (law of definite proportions)
all samples of a particular compound contain the same elements combined in the same proportions, always is the same
flammability
chemical intensive
scinetific notation
coefficient value must be 1 to less than 10 1.0 X 10^6 mg
physical changes
color, oder, taste, melting/boiling point, physical state (gas, liquid, solid), solubility, viscosity, density, hardness, softness, light enough to float, can be cut with sharp knife
extensive
does depend on the amount of matter, mass, length, volume (all will change if the amount of matter change)
intensive
does not depend on the amount of matter, color, boiling point, hardness, temperature, density (all are independent of the amount you have)
rounding off sig figs
drop "insignificant" digits, only at the end of calculations
chemical changes
flammability, corrosion, oxidation, ability to rust, tarnish, react violently, decompose, ferment, candle burning, 2 clear colorless salt solutions are mixed and a bright orange precipate forms, changes from silver gray to black when placed in moist air, reacts violently with chlorine to form solid, produces a hole in container
celsius
freezing point is 0 degrees C, boiling point is 100 degrees C
significant figures
includes all digits known with certainty plus one digit that is uncertain; you always have to go one more digit from what you are actually able to see (doesn't matter which number you chose)
King Henry Died By Drinking Chocolate Milk
kilo, hecto, deka, base (or meters), deci, centi, milli
precision
measurements are close to each other
accuracy
measurements are close to known value
dimensional analysis
multistep conversion problem
mass
physical extensive
boiling point
physical intensive
color
physical intensive
properties of matter
physical or chemical and intensive or extensive
density
relates mass and volume togetehr temperature dependent mass/volume
multiplying and dividing sig figs
round to lowest number of sig figs in the problem
adding and subtracting sig figs
round to the least number of decimal places
molecular formula
shows the actual number of each type of atom in a molecule
empirical formula
shows the simplest whole number ratio of atoms in a compound
atom
smallest particle of an element which maintains its chemical properties
chemistry
study of composition, structure and properties of matter
weakest link principle
the number of sig figs in the final result cannot be greater than the "weakest link" used in the calculation
uncertain digit
the very last digit in a measurement
molecule
two or more atoms joined together by chemical bonds, can consist of atoms of the same element of different elements
measurements
two parts: number and unit
standardization
units of measurement is essential to ensure repeatability and facilitate communication among people around the world
