Open your lab notebook to your table of contents and fill in the information below Date Title Partners Pages 7 October Diffusion & pH (will be assigned)

Turn to the next blank page in your lab notebook and write the following: Title: Examining the rate of diffusion of unknown concentrations of acids and bases, into dH 2 O, using Vernier Probes.

Title: Examining the rate of diffusion of unknown concentrations of acids and bases, into dH 2 O, using Vernier Probes.

Materials Each group will have: 1 probe 1 beaker of dH2O 1 sample to test 1 clip to hold the sample

Each group will have:

1 probe

1 beaker of dH2O

1 sample to test

1 clip to hold the sample

Write the following in your notebook. Sample number: __________ Color of sample: ___________ Initial pH of dH 2 O: __________ Final pH of dH 2 O: __________ Sample# Slope of the line (m) Molarity 1 2 3 4 5

Sample number: __________

Color of sample: ___________

Initial pH of dH 2 O: __________

Final pH of dH 2 O: __________

IMPORTANT! These substances can burn your skin Do not get the Vernier probe bases wet Be gentle with pH probes

These substances can burn your skin

Do not get the Vernier probe bases wet

Be gentle with pH probes

Setting up your probe Give the probe to one person in your group. File, New Click Mode Click the white box next to “rate.” Type in 10 Click the white box next to “length.” Type in 5 Using the drop down menu and select “min.” Click “OK.”

Give the probe to one person in your group.

File, New

Click Mode

Click the white box next to “rate.” Type in 10

Click the white box next to “length.” Type in 5

Using the drop down menu and select “min.”

Click “OK.”

Plug in the pH probe into the top of the base where it says “CH 1.” Place the base into the plastic bag Unscrew the tube at the end of the pH probe Place the probe into a beaker of dH 2 O Watch the red box on the screen until the pH reaches between 7.3 and 7.5

Plug in the pH probe into the top of the base where it says “CH 1.”

Place the base into the plastic bag

Unscrew the tube at the end of the pH probe

Place the probe into a beaker of dH 2 O

Watch the red box on the screen until the pH reaches between 7.3 and 7.5

Set up your sample Press the play button on the screen of the base.

Set up your sample

Press the play button on the screen of the base.

At the end of 5 minutes Graph button Analyze Curve fit of pH Choose fit, linear Write down the “m” number

Graph button

Analyze

Curve fit of pH

Choose fit, linear

Write down the “m” number

Sample# Slope of the line (m) Molarity 1 2M HCl 2 1M HCl 3 Water 4 1 M NaOH 5 2 M NaOH

What is Molarity? Molarity is a measure of grams of a substance per liter. M = g/L The higher the Molarity, the higher the concentration of a substance.

Molarity is a measure of grams of a substance per liter.

M = g/L

The higher the Molarity, the higher the concentration of a substance.

Analysis Draw the general shape of each graph How does Molarity relate to rate of diffusion? For each solution was the water hypotonic, hypertonic or isotonic to the sample in the bag?

Draw the general shape of each graph

How does Molarity relate to rate of diffusion?

For each solution was the water hypotonic, hypertonic or isotonic to the sample in the bag?