Section 1: Chemistry & Experimentation Chemistry: Study of composition, structure, and properties of matter
Used for the following: Producing metals, glass, and dyes Alchemy: An earlier form of chemistry that did not use the scientific method and had a mystical approach without a physical rationalization. Used for the following: Producing metals, glass, and dyes Separating Mixtures Purifying chemicals https://www.youtube.com/watch?v=7ealYU2ICnU
Scientific Method: Procedure used to test an observation. Make an observation Form a proposed explanation for the observation (hypothesis). Test the hypothesis using dependent and independent variables Interpret results to see if it supports the hypothesis. If the hypothesis is supported, begin to form a theory or create a new hypothesis to be tested. Compare your findings to others to create common theories and laws in the scientific community.
The Nature of Science: A hypothesis can evolve to a theory if supported by enough of the scientific society. A theory cannot be proven and is always open to be revised.
Independent Variable: The part of the experiment that you change or manipulate. Dependent Variable: The part of the experiment that is affected by the change.
Types of Data Qualitative data: Data used to describe Quantitative data: Data that measures numerically. Demo: Qualitative: Quantitative
Models: Used to help describe laws and theories in forms of structures, pictures, and equations. Laws: Explain what will happen, not why. Theory: Explains why things happen once tests have been repeated confirming the hypothesis. These can be proven wrong.
Burning wool lab: (set up lab) Objective: Burn wool in a crucible and determine what happens to the mass of the system. Hypothesis: If the iron burns in the presence of oxygen, then the mass will ________________________. Procedure: 1) Place the wool in a steel crucible and weigh it. 2) Place the crucible in the ceramic triangle and heat it for 5 minutes. Allow the system to cool for 4 minutes are reweigh. Data: Mass of crucible before reaction:______ Mass of crucible after reaction:______ Change of mass:_____
Questions and Analysis Find 3 other groups and record if their mass increased or decreased. Name a few sources of error in the lab that could affect the outcome of the final mass. 3) What could have caused the mass to change the way it did? What happens in a chemical reaction? Based on your data, how much oxygen was consumed. Write the equation for the reaction:
Classwork / Homework Pg 25 (16-25)