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Mr McCondichie

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Acids and Alkalis

Lesson 1 - Making, Testing and Using Hydrogen

Learning Intentions

Starter

What do you know about hydrogen?

Notes - Hydrogen

Hydrogen is an element.

This means that hydrogen is made up of atoms of one kind only.

The chemical symbol for hydrogen is H.

At room temperature hydrogen is a gas.

Activity - Making and Testing Hydrogen

  1. Write and underline the title, 'Making and testing hydrogen'.
  2. Collect a copy of the diagram below and stick it into your jotter.
  3. Copy table below into your jotter under and give it the heading 'Results'
  4. Test Tube Observation
    1
    2
    3
  5. Collect the equipment in the list below.
  6. Follow your teacher's instructions for the experiment.

Results

Notes - Properties of Hydrogen

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Lesson 2 - The Properties of Hydrogen

Learning Intention

Notes - Planning an experiment

Before scientists do an experiment they make a hypothesis.

They write down what they think their experiment will show them and why they think that.

Activity 1 - Is hydrogen more dense or less dense than air?

Collect a copy of the worksheet in the picture below.

Write down what you think (hypothesize) will be formed when hydrogen burns in air.

Collect the following equipment:

Do the following or as instructed by your teacher:

  1. Put on safety goggles
  2. Test Tube 1
  3. Hold the test tube upside down
  4. Take off the stopper.
  5. Wait 30 seconds keeping the test tube upside down.
  6. Test with a burning splint. Is any hydrogen left in the test tube?
  7. Repeat with Test Tube 2, this time holding it the right way up for thirty seconds. Is there any hydrogen left this time?

Results - density of hydrogen

Draw a labelled diagram of the two test tubes.

Copy and complete:

Hydrogen gas is more/less dense than air.

Activity 2 - What happens when water is added to cobalt chloride paper?

Write down what you think (hypothesize) will happen to the cobalt chloride paper and why.

Do the following:

  1. Put on safety goggles
  2. Collect a small beaker of water.
  3. Get one piece of dry cobalt chloride paper.
  4. Get a dropper.
  5. Drop two drops of water onto the cobalt chloride paper.

Results - Adding water to cobalt chloride paper

Copy and Complete:

Cobalt chloride paper is b___ when dry and p___ when wet.

Activity 3 - What new substance is made when hydrogen burns?

Write down what you think (hypothesize) will happen when hydrogen is burnt and why.

Do the following:

  1. Make or collect a test tube of hydrogen.
  2. Take off the stopper.
  3. Use a lighted splint to do the 'pop test'.
  4. Put a piece of dry cobalt chloride paper to the test tube and re-stopper it.
  5. Wait.

Results - Burning Hydrogen

Copy and Complete:

When h_______ burns or explodes, it combines with o_____ from the air to form w____.

The chemical name for water is hydrogen oxide.

The word equation for the reaction is:

hydrogen + oxygen → water

The chemical formula for water is H2O.

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Lesson 3 - Making Hydrogen from water

Learning Intentions

Activity - What happens when an electric current is passed through water?

Glue a picture of the Hoffman voltameter into your jotter, and copy this table:

Electrode Gas made Test Used
Negative Electrode
Positive Electrode

What happened when your teacher switched the electricity on?

Do the following:

  1. Complete the table
  2. Collect a copy of Chemical Science 3. Read pages 28-30. Answer questions 1-3 in your jotter.
  3. Collect Starting Science 2. Read pages 16 and 17, and answer the questions on each.

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Lesson 4 - Metals and Water

Learning Intentions

Notes - Metals reacting with water

Certain metals when they react with water are also capable of producing hydrogen from water.

Activity - Alkali Metals Reacting With water

Watch your teacher demonstrate the alkali metals reacting with water.

The video below shows the bigger pieces of alkali metals reacting with water as well as some that can't be done in school.

Activity - Other Metals that React with Water

Copy the table below into your notes:

Metal Reaction with Water Test for Hydrogen
magnesium
iron
calcium

Collect the following equipment:

Watch your teacher demonstrate this experiment then follow the instruction below:

  1. About 2cm of water in each test tube.
  2. Add magnesium to your first test tube.
  3. Test to see if hydrogen gas is produced.
  4. What did you see?
  5. Write this down in your results table.
  6. Do steps 1-5 again with calcium then with iron.

Results

Do the following:

  1. Method: Draw a labeled diagram of your experiment and equipment.
  2. Conclusion: copy and complete the conclusion below:

The metal that reacts most with water is c______.

The metal that reacts least with water is i___.

Some metals react with water to make h_______ gas.

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Lesson 5 - Metals and Acids

Learning Intentions

Activity - Reaction of Metals with Acids

Copy the table below:

metal observation
magnesium
iron
tin
zinc
copper
aluminium

Collect the equipment below:

Watch your teacher demonstrate the experiment then follow the instructions below:

  1. Collect a bottle of acid.
  2. Add about 2cm of acid to each test tube.
  3. Add one bit of magnesium to your first test tube.
  4. Test to see if hydrogen has been given off.
  5. Write what you see in your results table.
  6. Repeat for the remaining metals.

Notes - Metals and Acids

To solve the anagram put the first letter of the metal's name in order of reactivity.


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Lesson 6 - Making an Indicators

Learning Intention

Red Cabbage Indicator

Click on the image below to watch the video below on making red cabbage indicator.

Extension

Use the information from the video to write a set of instructions for making red cabbage indicator.

Activity - Making an Indication

Copy this diagram, and label it using the words:

Tripod Stand   100cm3 Beaker   Red Cabbage   Water

Copy the table below into your jotter.

substance colour change
water no change
acid purple → ___
alkali purple → _____

Collect the following items:

Watch your teacher demonstrate how to carry out this experiment then:

  1. Cover the red cabbage with 50cm3 of water.
  2. Boil the Red Cabbage for 4 minutes.

Results

Answer the following questions in sentences in your jotter.

  1. What vegetable did you use to make the indicator?
  2. What colour was the indicator you made?
  3. What colour did your indicator turn in acid?
  4. What colour does your indicator turn in alkali?
  5. A mystery solution turns your indicator red. Was it an acid or and alkali?
  6. Can you explain your answer?

Notes - Indicators

Copy and complete the notes below into your jotter.

An indicator is a dye that changes colour in different conditions.

Fruits and vegetables can be used to make indicators.

In class we used R__ C______ to make an indicator.

The colour changes I noticed were:

Acid   P_____ → R__

Alkali   P_____ → G____

Extension - Other indicators

Turmeric as an indicator.

Bicarbonate Soda as an indicator.

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Lesson 7 - Investigating the pH Scale

Learning Intentions

Notes - Universal Indicator

Universal indictor is a special dye that when added to a solution (liquid) is:

Red-orange in acid

green in neutral solutions

blue - purple in alkali

Activity - Testing pH of Household Substances

Copy the table below into your notes. You will need space for nine rows.

Name of substance Colour of Universal Indicator pH number Acid, alkali or neutral

Equipment

Collect the following equipment:

Instructions

Follow the instructions below.

  1. Add 5 drops of your first solution (liquid) to one of the holes in the dimple tile
  2. Add 2 drops of universal indicator.
  3. Use your pH chart to help you find the pH number.
  4. Write down your results before testing the next solution.

Notes - The pH Scale

Copy and complete the notes below into your notes.

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Lesson 8 - Neutralisation

Learning Intentions

Activity - Neatralisation

Equipment

Instructions

  1. Put 3cm3 of hydrochloric acid in a test tube.
  2. Add a few drops of indicator.
  3. Carefully, drop by drop, add the alkali (sodium hydroxide) until you neutralise the acid (ie it goes green). This can be rather tricky! Then stop

Results

Answer the following questions in sentences.

  1. How did you neutralise the acid?
  2. How did you know the acid had been neutralised?
  3. Describe any difficulties you had.

Activity - Indegestion Tablets

When people get heartburn or indigestion they often take antacid tablets to neutralise the acid in their stomach.

Equipment

Instructions

  1. Put 100ml of “stomach acid” into a 250ml beaker.
  2. Add 5 drops of universal indicator.
  3. Slowly add the crushed antacid tablet.
  4. Stir the mixture until the solution is neutral (ie goes green).

Notes - Neutralisation

Copy and complete.

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Lesson 9 - Making a Salt

Learning Intentions

Activity - Making a Salt

Equipment

Collect the Following Equipment

Neutralisation - Instructions

Watch your teacher demonstrate the experiment then follow the instructions on the worksheet

  1. Write a sentence that describes how you made the neutral solution, and any problems you had.
  2. Copy the diagram on side two of the sheet.
  3. Copy the box.
  4. Save your solution for the next lesson.
  5. Evaporation - Instruction

    Equipment

    Collect the Following Equipment

    Watch your teacher demonstrate evaporation then follow the instructions on the worksheet.

    Notes - Neutralisation

    When an acid and an alkali are mixed in the correct proportions, a neutral salt solution and water are formed - this is called neutralisation.

    Word equation:

    Acid + Alkali → salt + water

    Sodium hydrixide + hydrochloric acid → sodium chloride + water

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    Lesson 10 - Acid Rain

    Learning Intentions

    How is acid rain formed?

    Acid rain is caused by the gas sulphur dioxide which is produced when fossil fuels are burned.

    It reacts with water in the atmosphere, then falls as 'acid rain'.

    Power stations in Scotland burn coal to produce over 100,000 tonnes of sulphur dioxide every year.

    Activity - Acid Rain Poster

    Your task is to make a poster that answers one of the questions in the learning intentions.

    You will find the following information helpful but you may also wish to do your own research.

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    Lesson 11 - The Effects of Acid Rain on Buildings

    Learning Intentions

    Activity - The reaction of metal carbonates with acid

    Copy the table below into your notes.

    Metal Carbonate Acid Used Observation Gas Produced
    Calcium carbonate

    Equipment

    Collect the following equipment:

    Instructions

    1. Put some limewater into a test tube.
    2. Place 1 spatula of calcium carbonate to a boiling tube add 2cm3of acid.
    3. Fit the delivery tube to the boiling tube.
    4. Test the gas released by bubbling it through limewater.

    Results

    Copy and complete the note below.

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    End of Topic Quiz