Acid Exploring Station 1

​Can acids conduct electricity?

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What is the effect of acids on indicators?​

​Some text here about the topic of discussion.

What are we exploring today?

An acid is a substance that produces hydrogen ions, H+ in aqueous solution.​

​

What is an acid?

​

acid​

​H⁺

​H⁺

​H⁺

​An acid is a substance that dissolves in water to produce hydrogen ions

Open Ended

Name three acids that you know of.

Is dry HCl gas an acid?

Some text here about the topic of discussion

As HCl is not dissolved, there are no hydrogen ions produced.

Since it is dry, there is no presence of water to dissolve HCl.

Multiple Choice

So is dry HCl an acid?

• Yes

• No

Not all that contain hydrogen are acids.

Substances like CH₄, H₂O​ and NH₃ contain hydrogen but they are not acids.

Multiple Choice

Why are these substances (CH₄, NH_3, H₂O) not considered as acids?

• There is no water.

• They do not dissociate into H⁺ ions when dissolved in water.

• They are insoluble.

HCl --> H⁺ + Cl^-​

​​Hydrochloric acid

HNO₃ -->

​​Nitric acid

H₂SO₄ -->

​​Sulfuric acid

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​CH₃COOH --> CH₃COO^- + H⁺

​​Ethanoic acid

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​Constructing equation for the dissociation of acids

​The acid dissociates into hydrogen ion and its anion.

Draw

Construct the equation for the dissociation of nitric acid and sulfuric acid.

​To investigate this, you are given an acid pack.

​The acid pack contains:

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Can acids conduct electricty?

• Lemon

• LED

• Crocodile clips

• Magnesium ribbon

• Copper foil

​A conductor of electricity has free moving charged particles.

Click on the link to watch the video on how to set up.

Instead of salt solution, use a diluted acid (1 part acid, 3 parts water)​

​https://www.youtube.com/watch?v=8aGfwFH4Fzc

Setting up the circuit.

Poll

Did the bulb light up?

• Yes

• No

Multiple Choice

Can acids conduct electricity?

• Yes

• No

Acids dissolve in water to form solutions which conduct electricity.

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When acids dissolve in water, they produce free moving hydrogen ions.

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The presence of free moving hydrogen ions (charged particle) allows acids to conduct electricity.

How does an acid affect indicators?

Find Universal Indicator and litmus papers in the lab.​​

Pour 1 cm depth of each acid (HCl, HNO₃, H₂SO₄) in three different test tubes. ​​

Wash a glass rod with deionised water. Dip the glass rod into HCl and touch the litmus papers with the same rod. ​​

Repeat step 3 with the two other acids. ​​

In each test tube, add a few drops of Universal Indicator.

Observe the colour change.

​1

2​

​3

​4

​5

​6

Fill in the Blanks

Acids turn blue litmus paper

.

Fill in the Blanks

Acids turns Universal Indicator

.

Physical Properties of Acids

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Acids have a sour taste

Acids dissolve in water to form solutions that conduct electricity

Acids turn blue litmus paper red and Universal indicator red - yellow

Multiple Choice

What does acids produce in water?

• H+ ions

• Hydroxide Ions (OH-)

• water

• salt

Multiple Choice

HI --> H⁺ + I^-

Is HI and acid? Why?

• Yes. It has hydrogen atom.

• No. It is a covalent molecule.

• Yes. It dissociates into H⁺

• No. It gives I^-

Multiple Select

Which of the following substances are considered ACIDIC? (Select all that apply)

• orange juice

• soap

• sulfuric acid

• gastric acid

Multiple Choice

Which of the following are properties of acids?

• They conduct electricity when dissolved in water

• They taste sour

• They react with metals to produce hydrogen gas

• All of the answer choices are correct

Multiple Choice

Taste of weak acids:

• Bitter

• Salty

• Sour

• Sweet