Kilo k 1000
hecto h 100
deca da 10
unit
1
deci d
0.1
centi c
0.01
milli m
0.001
mass in grams (g) A nickel weighs about 5g.
distance in meters (m) A nickel = 2 mm thick.
volume in liters (L) 1.057quarts
= 1.000 liters
Mass is a measure of the quantity of matter. Weight
is a measure of the force of gravity on an object.
English Units
Length
12 inches (in.) = 1 foot (ft)
3 feet (ft) = 1 yard (yd)
5280 feet (ft) = 1 mile (mi)
Mass
16 ounces (oz) = 1 pound (lb)
2000 lb = 1 ton
Volume
2 pints (pt) = 1 quart (qt)
4 (qt) = 1 gallon (gal)
English/Metric Conversions +
1 inch = 2.54 cm
1 pound = 453.6 g
1 quart = 0.946 L
1cm3 = 1 mL
Dimensional Analysis
Convert 27.2 ft. to meters (m).
27.2 ft x 12 in x2.54
cm x 1 m = 8.29 m
1
1ft 1 in
100 cm
Convert 99 oz to kg.
99 oz x 1 lb x453.6
g x 1 kg = 2.8 kg
1 16
oz 1 lb 1000 g
Convert 1.0 ft3 to L
1.0 ft3 x12
in3 x 2.54 cm3x1
mL x 1 L
= 28 L
1
1 ft3 1 in3
1 cm3 1000 ml
Density = mass/volume
solids; g/cm3
liquids; g/mL
gases; g/L
Sample densities
Au 19.3 g/cm3
H2O @ 4o C 1.00 g/mL
Air 1.29 g/L
Calculate the mass of 2500 mL of methane (density 0.714 g/L)
d = m ;
m = dv
v
m = (2500mL) (0.714g/L) (1L/1000mL) = 1.785 g = 1.8 g
What is the mass in lbs. of 1.00 gal. H2O.
1.00 gal x 4 qt x
1
L x 1000 mL x
1.00
g x1 lb = 8.34 lb
1 gal 1.057qt 1L
1 mL 453.6 g
Percentage = % = parts per 100
% = part x 100
whole
1
Unless specified otherwise, we will use % by mass.
14-karat gold (Au) is 41.6 % copper (Cu). Calculate the
mass of gold
in a 12.2 g 14-K gold ring. Let "R" stand for ring.
12.2 g R x 58.4 g Au = 7.12 g
Au
1
100. g R
% = part x 100
whole
1
58.4 = x
x 100
12.2 g
1
x = (58.4) (12.2 g) = 7.12 g Au
100
Temperature Scales
| oF | oC | K | |
| boiling point of H2O | 212 | 100 | 373 |
| freezing point of H2O | 32 | 0 | 273 |
| absolute zero | -460 | -273 | 0 |
Temperature Conversions
K = oC + 273
oF = 1.8oC + 32
oC = (oF - 32 )
1.8
Convert - 22oF to oC & K
oC = oF - 32
1.8
oC = (-22 - 32) = - 30.oC
1.8
K = 273 + oC
K = 273 + (-30) = 243 K
Energy = the capacity to perform work.
Common types of energy: mechanical, electrical, chemical,
light, heat
Law of Conservation of Energy: In a non nuclear process energy can neither be created or destroyed.
Potential energy = stored energy
Kinetic energy = energy due to the motion of matter
Units of Energy
J = Joule = kg m2
sec2
cal = calorie = heat needed to warm 1 g H2O from 14.5oC to 15.5oC
BTU = heat to warm 1 lb of H2O by 1oF
Specific heat (Sp. Ht.) = heat energy needed to warm 1 g of a substance by 1oC.
Examples
H2O(s) 2.1 J/goC
H2O() 4.184 J/goC
H2O() 1.00 cal/goC
Fe(s) 0.444 J/goC
O2(g) 0.92 J/goC
Heat is a measure of the quantity of energy while temperature is a measure of intensity.
Heat = (Sp.Ht.)(mass)( delta T)
delta T = Tfinal - Tinitial
Calculate the joules of energy needed to warm 55g Al from 25oC to 79o C
Heat = (Sp.Ht.)(mass)( delta T)
= 0.908 J x 55g x(79oC
- 25oC) = 2696.76 = 2700 J
goC
1
1
Heat always flows from a warm body to a cold body. The heat lost by the warm body equals that gained by the colder body. Heat lost is negative by convention because T = Tf - Ti < O.
A 60.0g Fe bar at 99.0oC is placed in
55.0 g H2O at 22.0oC. What is the final temperature.
- Heat Fe = + Heat H2O
- 0.444 J x (Tf - 99.0oC)
x
60.0g = 4.184 J x(Tf
-22oC)x 55.02
goC
1
1 goC
1
1
Tf = 30.0oC