Hopefully so, because this is pretty cool…

What does a proton taste like?: ” Drawing attention to the fact that the ability to detect ‘sour’ tastes is one of the least well-understood gustatory talents. But progress has recently been made, and the current view is that the detection of sour tastes is linked to the presence of hydrogen ions in the food. Since a normal hydrogen atom is composed of one proton and one electron, a hydrogen ion (missing its electron) can simply be thought-of as a free proton. Thus the sour-specific cells of mammalian tongues are, in effect, proton detectors.”

Had never thought of that. Completely makes sense, though!

Life, as we thought of it, requires six elements… nitrogen, oxygen, sulfur, carbon, hydrogen and phosphorous. Except we now realize phosphorous can be substituted with arsenic.

If you check out the periodic table, you’ll see that the elements phosphorous and arsenic are in the same family/group.

This is just amazing news…

All life on Earth – from microbes to elephants and us – is based on a single genetic model that requires the element phosphorus as one of its six essential components.

But now researchers have uncovered a bacterium that has five of those essential elements but has, in effect, replaced phosphorus with its look-alike but toxic cousin arsenic.

Washington Post: Second Genesis on Earth?

You can watch part of the NASA announcement video here.

And yes… this will be a TYPE 1 EXAM QUESTION on your exam

Homework 10: Acids, Bases and Solutions

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This week, we are studying acids and bases. These topics are a great bridge between the Fall and Spring semesters as we transition from the study of Chemistry to the study of Physics.

So, here’s your homework for the week:

Objective 1: Understanding Solutions

1. What are the characteristics of solutions, colloids, and suspensions?
2. What happens to the particles of a solute when a solution forms?
3. How do solutes affect the freezing point and boiling point of a solvent?
4. Suppose you mix food coloring in water to make it blue. Have you made a solution or solution or a suspension? Explain.
5. What effects do solutes have on a solvent’s freezing and boiling points?

Objective 2: Concentration and Solubility

1. How is a concentration measured?
2. Why is solubility useful in identifying substances?
3. What factors affect the solubility of a substance?
4. How does temperature affect the solubility of most solids?
5. How can solubility help you identify a substance?

Objective 3: Describing Acids and Bases

1. What are four properties of acids?
2. What are four properties of bases?
3. How can you use litmus paper to distinguish an acid from a base?
4. How might you tell if a food contains an acid as one of its ingredients?
5. Why is it wise to wear gloves when spreading fertilizer in a garden?

Objective 4: Acids and Bases in Solution

1. Which ion is found in acids?
2. Which kinds of ions do acids and bases form in water?
3. What ions will the acid HNO3 form when dissolved in water?
4. What does a substance’s pH tell you?
5. If a solution has a pH of 6, would the solution contain more or fewer hydrogen ons (H+) than an equal volume of solution with a pH of 3?

Objective 5: Digestion and pH

1. What are the two parts of digestion?
2. How do those two parts differ?
3. People who have lost most of their teeth may have trouble chewing their food. How does this affect their digestive process?
4. What is the pH in your mouth? Stomach? Small intestine?
5. Why are pH variations in different parts of the digestive system important to the process of digestion?

Objective 6: Key Terms

Define:

1. Acid
2. Neutralization
3. indicator
4. corrosive
5. hydroxide ion

HowStuffWorks “Why does fake gold turn your skin green?”: “When you buy a cheap, fake gold ring, it’s likely made of mostly copper. When you perspire, the metals in the ring react with the acid in your sweat to form salts, which are green. These acids are essentially causing the copper to corrode on the surface of the metal, which forms a salt compound of the metal. These salts are absorbed into the skin and the result is a decidedly green digit. This is nothing to be worried about; it’s not a metal allergy you’re suffering from. It simply means that the gold ring you thought was real is really just a cheap imitation. Metal allergies cause redness and swelling, not a dull green color. Another way to spot fake gold is that it can rust in high humidity or over time. “

The world is much more interesting when you know a little background information!

Remember, our 50 POINT test on Chapter 7 is tomorrow!

QUESTION 1
Which is not a type of mixture?
Solution
Colloid
Acid
Suspension

QUESTION 2
Sugar water is an example of a:
suspension
solution
solute
colloid

QUESTION 3
Ammonia is an example of a(n):
acid
base
salt
antacid

QUESTION 4
Acids produce __________ in water.
hydroxide ions
pH scale
solute
hydrogen ions

QUESTION 5
HCl is a common ________.
acid
base
salt
solution

QUESTION 6
Milk is a good example of which type of mixture?
acid
solution
base
colloid
suspension

QUESTION 7
A base produces ____________ in water.
hydroxide ions
salts
hydrogen
hydrogen ions

QUESTION 8
The names of acids normally end in _______.
-ide
-ice
-ixe
-ic

QUESTION 9
When acids react with magnesium, zinc and iron, _________ is produced.
salt
hydrogen gas
hydrogen ions
hydroxide ions

QUESTION 10
Salt is any compound that is made from the __________ of an acid with a base.
solubility
solution
reaction
neutralization
precipitation

Section 7.1:

Section 7.2:

Section 7.3:

Section 7.4:

Chapter 7 Wrap-Up:

Let me know if you have any questions!

1. What is a hydrogen ion?
2. What is the key to the reaction of acids?
3. Please give another definition of acids based on what we’ve learned about hydrogen ions.
4. What are many bases made from?
5. Describe the hydroxide ion
6. Please give another definition of bases based on what we’ve learned about hydroxide ions.
7. To what does the strength of an acid or base refer?
8. How does a strong acid differ from a weak acid?
9. What are some examples of strong acids?
10. What is an example of a strong base?
11. What is the pH scale?
12. What does a low and high pH tell you?
13. What is a “salt”?
14. What happens in a neutralization reaction?

Remember, your homework (due Monday) is 7.3 Section Assessment #1-2 on page 241.

1. What is an acid?
2. What are some common acids?
3. Acids taste a certain way… how do they taste and should you use that property to identify acids?
4. What does it mean to say that an acid is corrosive?
5. Which gas forms when an acid reacts with zinc, magnesium or iron?
6. What are the properties of a base?
7. What are three common bases?
8. Please give one safe way to identify a base.
9. What vitamin is an acid?
10. Which acid is used to clean bricks and metals?
11. Why is baking soda used in baking?
12. Drain cleaners are very potent materials. What substance do they contain and is it an acid or base?
13. Which substance is used to make fertilizers?
14. Where is folic acid found?

Also, check your grades over on http://www.mygradebook.com!

Remember, your homework is Section 7.2 Section Assessment p. 235 #1-3!

1. What is a dilute solution? Please give an example.
2. How does a concentrated solution differ from a dilute solution?
3. How can you change the concentration of a solution?
4. When you make juice from concentrate by adding water, are you making a dilute or concentrated solution?
5. How do you measure the concentration of a solution?
6. Why can you only add so much sugar to sweet tea?
7. What is a saturated solution?
8. What does the solubility of a substance tell you?
9. What factors affect the solubility of a substance?
10. How does pressure affect the solubility of gases?
11. How do solvents affect how well a solute dissolves in liquids?
12. How are the solubility of solids affected by temperature?
13. What is a supersaturated solution?
14. Is NaCl or baking soda more soluble in water?
15. As temperature increases, what happens to the solubility of a gas?

See you tomorrow!

Remember, your homework is the Section Assessment #1-3 on page 227!

1. What is a solution?
2. What is the difference between a solute and a solution?
3. What is the “universal solvent”? Give examples of these types of solutions.
4. What are some examples of solutions without water?
5. What is a colloid? Give an example.
6. Does a colloid or solution contain larger particles?
7. What is a suspension? Please give an example.
8. What is the difference between a solution and a suspension?
9. Why do solutes seem to disappear when you mix them with a solvent?
10. What happens when an ionic solid mixes with water?
11. What happens when a covalent (molecular) solid mixes with water?
12. How can you tell the difference between solutions of ionic compounds and solutions of covalent (molecular) compounds differ in water?
13. What do solutes do to the freezing point and boiling points of solvents? Please give an example.
14. How does salt lower the freezing point of water?
15. How does antifreeze use the properties of solutes and solutions to protect car engines?

See you tomorrow!