Y8 U2 - Solubility Practical - Pre-Lab

Y8 - Unit 2 Solubility
Practical

Pre-Practical Assessment.

Poll

What class are you in?

• Mr. Aidan

• Ms. Lene

• Ms. Sahbia

• Mr. Rob

This Quizizz is a pre-lab assessment!

This is graded.

This Quizizz aims to:
- Inform students about variables.
- Inform students on an example of a solubility experiment.
- Prepare students with hazards, safety and practical method for this practical.

The next slide is for students who would like to review "SOLUBILITY".

If you are confident in solubility, you can move to the next slide after the video.

The next slide is for students who would like to review "VARIABLES".

If you are confident in variables, you can move to the next slide after the video.

Match

Vocabulary and Definition - Match the following:

• Variable

• Control Variables

• Independent Variable

• Dependent Variable

• Procedure

Things that can change in an experiment.

What is kept the same

What is changed on purpose.

What is measured for each change as data

The steps or method that is followed.

• Things that can change in an experiment.

• What is kept the same

• What is changed on purpose.

• What is measured for each change as data

• The steps or method that is followed.

Match

Importance of each part of a practical experiment - Match the following:

• Control Variables (CV)

• Independent Variable (IV)

• Dependent Variable (DV)

• Procedure

To make it a fair experiment.

Only the change will affect results.

Get data to see if IV had any effect.

To perform the experiment.

• To make it a fair experiment.

• Only the change will affect results.

• Get data to see if IV had any effect.

• To perform the experiment.

Introduction:

During this practical, you will be given instructions at the start of the lesson on what you should do during this practical and how to fill out the "Lab Report".

Make sure you are aware of any potential safety risk and protective measures, the procedure you should follow and additional information by using this pre-lab assessment.

The Practical:

Investigating the effect of water temperature on dissolving sodium chloride.


(Page 55-56 in the Learner's Book)

The Practical:

Groups of 4-5;


4 Classrooms will each have a different temperature workstation.

The Practical:

4 Classrooms; 4 temperatures:

Each classroom will have a different temperature for you to use to measure the solubility of NaCl (sodium chloride). The teacher will perform a quick run through in terms of procedure for each temperature.

601 (AWI) - Ice Bath - 0-5^oC
604 (SSA) - Room Temperature - 20-25^oC
605 (RGA) - Heated - 60-90^oC (Student's Choice)
606 (SJA) - Boiled - 100^oC

Equipment - each classroom will have:

Beakers

Thermometers - to measure water temperature.

Spatula - to measure the solute.
Stirring rod - to stir the solution.
Scale/Balance - to measure the salt.

Measuring cylinder (100mL) - to measure volume of water.
Funnel - to fill measuring cylinder.
Heating Element - Kettle, Ice Bath

Method / Procedure:

1) Measure 50mL of water (temperature specific) and add to your beaker.
2) Record the mass of your beaker and water.
3) Measure Xg of sodium chloride and add it to your weighing boat.
4) Add the salt and stir continuously.
5) Repeat steps 4-5 until no more salt can be added.
6) Record the mass of your beaker and solution.
7) Calculate how much solute you have dissolved.
8) Repeat for other water temperatures (different classrooms).
9) Generate a table and graph for the results.

The Practical: Variables

Plot a graph

• The independent variable always goes along the horizontal axis.

• The dependent variable always goes up the vertical axis.

Hotspot

Which speech bubble demonstrates the independent variable?

Click on the speech bubble to give your answer.

Hotspot

Which speech bubble demonstrates the dependent variable?

Click on the speech bubble to give your answer.

Hotspot

So that only the independent variable will affect the results we obtain, which speech bubble suggests this variable needs be to controlled to ensure the experiment is a fair test?

Click on the speech bubble to give your answer.

Complete the following questions as part of your pre-lab preparation and assessment.

Multiple Choice

Solutions are composed of __________ .

• salts and solutes
• solvents and salts
• solutes and alloys
• solutes and solvents

Multiple Choice

What apparatus will you use to measure mass?

• Ruler
• Thermometer
• Balance
• Spatula

• Measuring cylinder

Multiple Choice

Which apparatus measures volume?

• Ruler
• Thermometer
• Balance
• Spatula

• Measuring cylinder

Multiple Select

Which step(s) involves the use of spatula?

• 2

• 3

• 4

• 5

• 6

Open Ended

Step 5 will require which piece of apparatus to mix the solvent and solution?

Open Ended

Suggest a hazard that is present within this practical investigation.

Open Ended

Suggest a way students can stay safe during this specific experiment; give a reason why.

Reorder

Reorder the following:

• Record the mass of your beaker.

• Measure 50 mL of water; add it to the beaker using a funnel.

• Record the mass of your beaker and water.

• Measure the amount of NaCl you want to add in a weighing boat.

• Add the salt from the weighing boat to the beaker of water and stir.

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Reorder

Reorder the following:

• Add an additional measured amount of salt using the weighing boat and stir until the solution is saturated.

• Record the mass of the solution.

• Calculate the solute mass dissolved.

• Repeat the practical procedure with different solvent temperatures.

• Generate a graph using your tabulated data (data from your table).

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Multiple Choice

How does stirring the solution affect the rate of dissolving salt in water?

• Stirring the solution has no effect on the rate of dissolving salt in water.

• Stirring the solution decreases the rate of dissolving salt in water.

• Stirring the solution causes the salt to evaporate from the water.

• Stirring the solution increases the rate of dissolving salt in water.

Multiple Choice

Explain why adding more salt to a fixed amount of water may reach a point where no more salt can dissolve.

• Adding more salt to a fixed amount of water may reach a point where no more salt can dissolve because the water becomes saturated at its solubility limit.

• Adding more salt to water will make it evaporate faster

• The salt will disappear if more is added

• The water will turn into a solid if more salt is added

Multiple Choice

What is the term used to describe a solution that has dissolved all the solute it can hold at a given temperature?

• saturated solution

• dilute solution

• concentrated solution

• unsaturated solution

• maximized solution

Multiple Choice

Describe an experiment you could conduct to determine the solubility of salt in water at different temperatures.

• Mixing salt with oil instead of water

• Using different types of salt for each temperature

• Conduct a series of experiments by preparing saturated salt solutions at different temperatures and recording the temperature at which no more salt can dissolve.

• Measuring the solubility of sugar instead of salt

Multiple Choice

Use this graph to estimate the solubility of KCl at 70 ^oC.

• about 48 g

• about 42 g

• about 40 g

• 50 g

Multiple Choice

Use the graph to estimate the temperature at which 120 grams of KNO3 dissolves in 100 g of water.

• 60 ^oC

• 65 ^oC

• 70 ^oC

• 20 ^oC

Multiple Choice

At 80^oC, KBr's solubility is:

• 100g

• 90g

• 80g

• 0g

Multiple Choice

At which temperature do KBr and KNO3 have the same solubility?

• 60 ^oC

• 55 ^oC

• 50 ^oC

• Never