Chemistry and Applied MathWe’ll use math quite a lot in this class. Although a gooddeal of this class is qualitative in nature, some concepts(gas laws, molarity, and several others) use math.Scientiﬁc notation. Sometimes we will use incrediblylarge or small numbers that necessitate the use ofscientiﬁc notation. For example in measuring thenumber of atoms in a 10.00 gram sample of iron (Fe) orwhen we talk about the mathematical basis for the pHscale.
Scientiﬁc Notation... an example• The mole 6.02 x 1023• We celebrate National Mole Day on October 23rd!• 1.00– 9.99 x 10exponent• 1000 becomes... 1.00 x 103• More on calculations later…
Units of Measure• Volume: ml, l (milliliter/liter)• Mass/weight: g, kg (gram/kilogram)• Length: mm, cm (millimeter/centimeter)• Temperature: oC (degrees Celsius)
Density/Speciﬁc Gravity1. Density: Mass (weight) per unit volume2. D = M/V3. Measure mass by balance (grams)4. Measure volume by displacement or length-width-height5. Speciﬁc Gravity= Density Substance A/Density of WaterHow would you calculate the density of?• Unknown liquid• Cube of wood• Small rock• Air
Dimensional Analysis1. You have probably noticed that the periodic table features an arrangement ofelements with the following information 6 (atomic number) C (symbol) 12.01 (atomic weight)2. The atomic weight is the weight of one mole of carbon atoms (6.02 x 1023).3. Using a concept called dimensional analysis we can ﬁnd out how manyatoms there are in 91.00 g.91.00 g C x 1.00 moles C x 6.02 x 1023 atoms = 4.56 x 1024 atoms 12.01 g C 1.00 moles C
Speciﬁc Heat1. Speciﬁc Heat: Number of calories or joules of energy required to raise thetemperature 1.0 gram of a substance 1.0oC. The property has wide-reachingapplications in the physical, chemical, and biological world.2. Remind me about The Blubber Glove activity! Speciﬁc Heat = Cal Grams x oC3. Water has a speciﬁc heat of 1.0 Calorie per 1.0 gram per 0C