1Concepts of numbers in science:
- Units of measurment
- Quantities that are measured and calculated
- Uncertanity in measurment
- Significant figures
- Dimensional analysis
2Many topics of chemisty are _______.
3The base units used in th metric system:
- Mass-gram(g)
- Length-meter(m)
- Time- second(s or sec)
- Temperature- degree Celcius (*C) or Kelvins (K)
- Amount of a substance- mole (mol)
- Volume- cubic centimeter (cc or cm^3) or liter (L)
4What is the measure of the amount of material in an object?
5What is the measure of distance?
6Is considered the hotness or coldness of an object that determines the direction of heat flow?
7Heat flows spontaneously from an object with a ______ temperature to an object with a ___ temperature.
- higher, lower
- lower, higher
8What scale is based on the properties of water?
9What is the SI unit of temperature?
10Kelvin:
- It is based on the properties of gases.
- There are no negative Kelvin temperatures.
- The lowest possible temperature is called absolute zero (0 K).
11Celcius:
- 0*C is the freezing point of water.
- 100*C is the boiling point of water.
12To figure out K:
- K=*C - 273.15
- K = *C + 273.15
13What is a physical property of a substance?
14Density:
- D = m/V
- The most common units are g/mL or g/cm3
- It has units that are derived from the units for mass and volume.
15____ numbers are counted or given by definition. For example, there are 12 eggs in 1 dozen.
16_____ (or measured) numbers depend on how they were determined. Scientific instruments have limitations. Some balances measure to ±0.01 g; others measure to ±0.0001g.
17________ refers to the proximity of a measurement to the true value of a quantity.
18_____ refers to the proximity of several measurements to
each other.
19Significant Figures (SIGFIGS):
- All nonzero digits are significant
- Zeroes between two significant figures are themselves significant.
- Zeroes at the beginning of a number are never significant.
- Zeroes at the end of a number are significant if a decimal point is written in the number.
20When addition or subtraction is performed, answers are rounded to the least significant _______ ________.
21When multiplication or division is performed, answers are rounded to the number of digits that corresponds to the ______ number of significant figures in any of the numbers used in the calculation.
22A ___ weight is the sum of the atomic weights for the atoms in a chemical formula.
- Formula weight
- molecular weight
23A ____ weight is the sum of the atomic weights of the atoms in a molecule.
24A ____ ___ is the mass of 1 mol of a substance
25The molar mass of an element is the
- The formula weight (in amu’s) will be the same number as the molar mass (in g/mol).
- atomic weight for the element from the periodic table. If it is diatomic, it is twice that atomic weight.
26= most correct term when referring to ionic compounds
- Molecular weight
- Formula Weight
- Molar Mass
27= most correct term when referring to covalent molecules
- Molecular Weight
- Formular Weight
- Molar Mass
28= can use with either ionic or covalent compounds
- Molecular Weight
- Formular Weight
- Molar Mass
29___ provide a bridge from the molecular scale to the real-world scale.
30Formula of Moles
- moles= mass (grams) / molar mass
- JUST STUDY THE FORMULA
31The study of the mass relationships in chemistry
32An Example of a Stoichiometric Calculation: How many grams of water can be produced from 1.00 g of glucose?
C6H12O6(s) + 6 O2(g) → 6 CO2(g) + 6 H2O(l)
- There is 1.00 g of glucose to start.
- The first step is to convert it to moles.
33The ____ reactant is the reactant present in the smallest stoichiometric amount (what you will run out of first)
34The _____ reactant is used in all stoichiometry calculations to determine amounts of products and amounts of any other reactant(s) used in a reaction.
35_____ are defined as homogeneous mixtures of two or more pure substances.
36The ____ is present in greatest abundance.
37A ___ is a substance that is dissolved in a solution
38The ___ is a substance in which it dissolves to produce a homageneous mixture.
39When water is the solvent, the solution is called an
- aqueous solution
- solid solution
40Aqueous Solutions:
- Some molecular substances react with water when they dissolve.
- Molecular compounds interact with water, but most do NOT dissociate.
- Ionic Compounds dissolve by dissociation, where water surrounds the separated ions.
41Molarity:
- Molarity is one way to measure the concentration of a solution
- We call the amount dissolved its concentration.
- The quantity of solute in a solution can matter to a chemist.
42Molarity formula is:
Molarity (M)= moles of solute/ volume of solution in liters
43Dilution:
- using a pipet to deliver a volume of the solution to a new volumetric flask, and
- adding solvent to the line on the neck of the new flask.
44____ is an analytical technique in which one can calculate the concentration of a solute in a solution.
45A solution of known concentration is used to determine the unknown concentration of another solution.
- equivalence point
- standard solution
46When the reaction is complete it is at the
- equivalence point
- distance point
47Arrhenius
- An acid is a substance that, when dissolved in water, increases the concentration of hydrogen ions.
- A base is a substance that, when dissolved in water, increases the concentration of hydroxide ions.
48Bronsted-Lowry
- An acid is a proton donor.
- A base is a proton acceptor.
49In pure water, a few molecules act as bases and a few act as acids.
This is referred to as
50If a solution is neutral
- [H+] = [OH–].
- [H+] > [OH–]
- [H+] > [OH–]
51If a solution is acidic
- [H+] = [OH–]
- [H+] > [OH–]
- [H+] < [OH–]
52If a solution is basic
[H+] < [OH–]