chemistry - chapter 1 introduction to chemistry

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    CHEMISTRY

    Chapter 1: Introduction to Chemistry

    1.1 Chemistry

    Definition: Chemistry is the study of the ________________ and the______________________ and the changes it undergoes.

    There are 3 main branches of Chemistry:

    a. Inorganic Chemistry specializes in substances without carbon

    b. Physical Chemistry specializes in description and behaviour of

    chemical substances

    c. Biochemistry specializes in composition of living organism

    1.2 Chemical in Daily Life and Its Importance

    Chemical is everywhere around us. All matter is chemicals.

    Some chemical are synthetic while some are natural.

    Chemicals can be found in food, medicine, vitamin, glue, clothing, paint,

    household cleaning products and everything around us.

    Chemicals are used in almost every aspect of our lives. Examples:-

    a. Sodium chloride is used as salt

    b. Acetic acid is used as food preservatives

    c. Barium sulphate is used in paints

    d. Ammonia is used to make fertilizer and explosive

    e. Magnesium hydroxide is used in toothpaste to neutralize acid

    Chemistry related

    careers Chemistry related industries It will provide a wide range of useful1. Doctor products for consumers and contribute2. Pharmacist greatly to economy, society and3. Biochemist development of our country4. Food Technologist5. Chemical Engineer 1. Petroleum industry6. Forensic Scientist 2. Palm oil

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    industry7. Nutritionist 3. Agrochemical industry

    4. Rubberindustry5. Natural Gas Industry6. Plastic

    Industry

    1.3 Scientific Method

    Scientific method is a systematic method used to solve problems in

    science.

    Making Observation

    Gathering information about a phenomenon using our sensesEg: Hot water turns colder when it is left at room temperature

    Making an inferenceMaking a tentative explanation about a phenomenon based onoebservation

    Eg: The hot water turns colder because its temperature changes

    Identifying the Problem

    Asking a question based on the inference madeEg: How does the temperature of the hot water change when the hotwater is left?

    Making hypothesisMake a general statement about the relationship between amanipulated variable

    and a responding variable to explain the questions askedEg: The longer the hot water is left at room temperature, the lower isthe temperature

    Identifying VariablesManipulated Variable - variable that is changed in anexperimentResponding Variable - variable that respond / changes with theexperimentControlled Variable - variable that is kept constant throughout theexperiment

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    Eg:Manipulated Variable - Time taken to cool down thewater

    Responding Variable - Temperature of water

    Controlled Variable - Pressure

    Controlling VariablesDecide how to manipulate the chosen variables, what to be measuredand

    how to keep the controlled variables constantEg: The temperature of water is measured at intervals of 1 minute for a

    period of

    5 minutes and also measured at atmospheric pressure.

    Planning Experiment

    Determine the list of material and apparatus, procedure of experiment,method of collecting data, ways to analyse and interpret the datacollected

    Eg:

    Material: Hot water

    Apparatus: Thermometer , stopwatch, beaker

    Procedure: 1)A beaker is filled up with hot water2) The initial temperature of water is recorded andstopwatch is

    started

    3) The temperature of water is measured atatmospheric pressure

    Results:

    Time (min)Temperature of water

    0

    1

    2

    3

    Collecting DataMaking observation or measurements, and then record the datasystematically

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    Interpreting DataOrganise and analyse thedata recordedCan be interpretated in graphs, charts orcalculations

    Making ConclusionMaking a statement about the outcome of the experiment and whetherthehypothesis is accepted orrejected.Eg: The temperature of hot water decrease with time. Hypothesis isaccepted

    Writing Report

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