How do we determine differences in water (bottled vs tap)?

Agenda for Tuesday Sept 13th 1.Quiz2.Sensory Thresholds Lab

Learning Targets1. Use proper vocabulary when talking about solutions

and concentrations.2. Describe their sensory thresholds and their

classmates and be able to explain why they differ.

Vocab

• Solute – stuff we want to dissolve

• Solvent – substance in which we dissolve something

• Solubility – maximum amount of solute that can dissolve in a solvent– Different for different substances– Depends on pressure & temp

• Concentration – amount of a solute dissolved in a given volume of solution– A lot of solute is called concentrated– Little solute is called dilute

If a concentration is dilute, what does that mean?

Agenda for Wednesday Sept 14th 1.Review Vocab2.Lab

Learning Targets1. Use proper vocabulary when talking about solutions

and concentrations.2. Describe their sensory thresholds and their

classmates and be able to explain why they differ.

Define solute and give an example.Agenda for Thursday Sept 15th 1. Discuss lab2. Finish Lab Q’s and graph3. Start Dilution lab

Learning Targets1. Use proper vocabulary when talking about solutions and

concentrations.2. Describe their sensory thresholds and their classmates and

be able to explain why they differ.

Pop Quiz

1. Define solute and give an example

2. Define Solvent and give an example

3. What is concentration?

4. What does dilute mean?

http://www.noiseaddicts.com/2009/03/can-you-hear-this-hearing-test/

Sensory Threshold

• a level, point, or value above which something is true or will take place and below which it is not or will not – Minimum level to produce a response

• Different for different people – WHY?– Unique biochemistry– Age, environment, state of health

Sensory Threshold• Other thresholds?

• Animals– Bloodhound’s smell is 1 million times more sensitive– Cat’s eye is 8 times more sensitive– Our eyes has 200,000 light receptors, a buzzard has

over 1 million– Missing pigments – color blind– Catfish has sensors covering their body

Million vs Billion

• A million seconds is 12 days • A billion seconds is 31 years • A trillion seconds is 31,688 years. • Million=1,000,000 • Billion=1,000,000,000 • Trillion=1,000,000,000,000

• A million minutes ago was – 1 year, 329 days, 10 hours and 40 minutes ago.A billion minutes ago was just after the time of Christ

• A million hours ago was in 1885.A billion hours ago man had not yet walked on earth

• Since each dollar bill weighs about a gram and each pound has about 454 grams, a million dollars in one dollar bills weighs about 2202.6 pounds.

• In 20 dollar bills, a million dollars would still weigh 110 pounds.

• In 100 dollar bills, it would weigh 22.0 pounds.

How much powdered drink mix is actually in the cup?

• Most things are present in very low amounts– Bottled water and tap water

• Would use difficult fractions

Parts per Million/Parts per Billion

• 1/1,000,000 = .0000001• 1/1,000,000,000 = .0000000001

What is a threshold?

Agenda for Friday Sept 16th 1.Finish talk on ppm/ppb2.Lab

Learning Targets1. Increase understanding of concentration2. Develop an understanding of the use of ppm as a

way to express concentration

Parts per Million/Parts per Billion

• 1/1,000,000 = .0000001• 1/1,000,000,000 = .0000000001

• a way of expressing very dilute concentrations of substances– Usually describes the concentration of something

in water or soil