Chap. 10: pH, Acids, and Bases Flashcards Preview

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Flashcards in Chap. 10: pH, Acids, and Bases Deck (13)
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1

 

pH

Per Hydrogen.

The measure of the concentration of H+ in a solution.

2

 

Acid

Donate H+ ions into a solution.

For example:

HCl  →  H+  +  Cl-

Acids also come in different strengths. The more moles of H+, the stronger the acid.

3

 

Base

There are two ways to define bases:

1.) Put OH- into a solution.

NaOH → Na+ + OH-

2.) Remove H+ from a solution.

NH3 + H2O ⇔ NH4+ + OH-

4

 

H+ Ions

Acidic.

Increase in H+, decrease in OH-.

 

5

 

OH- Ions

Basic.

Increase in OH-, decrease in H+.

6

 

pH and Water

Water and H+ and OH- will go back and forth with each other until a state of equilibrium is reached.

 

H2O  ⇔  H+  +  OH-

or

H2O + H2O ⇔  H3O+  +  OH-

(Both of these are correct, both are used)

7

 

pH Scale

Acidic (more H+ ions) = pH of -1 to 6

101 =  –1 (concentrated HCl)

100 =  0 (battery acid)

10-=  1 (lemon juice) 

10-3 =  3 (vineger, soft drink, beer)

10-4 =  4 (tomato, coffee)

10-5 =  5 (urine, rainwater)

10-6 =  6 (milk)

*Neutral* 10-7 =  7 (pure water, blood, seawater)

10-8 =  (seawater)

10-9 =  9 (baking soda)

10-10 =  10 (soap)

10-11 =  11 (ammonia)

10-12 =  12 (hair remover)

10-13 =  13 (oven cleaner)

Basic (more OH- ions) = pH of 8 to 14

 

8

 

Acids and Bases

HCl + NaOH → H2O (l) + NaCl

*This is also a double-displacement reaction.

1 mole HCl + 1 mole NaOH → 1 mole H2O

2 moles HCl + 4 moles NaOH → Basic 

9

 

pH = -log10[H+]

H2O ⇔ H+ + OH-

1 in every 10 million water molecules are reacting this way. Therefore:

pH = -log10[H+]

 

10

 

What is the pH of a solution that has a hydronium-ion concentration of 0.001M?

The number 0.001 is 10-3 (by moving the decimal point three places to the right), therefore:

 

pH = – log [H3O+]

= – log [10-3]

= – ( –3)

pH​ = 3

11

 

What is the pH of a 0.01M solution of HCl?

The number 0.01 is 10-2 (by moving the decimal point two places to the right), therefore:

 

pH = – log [H3O+]

= – log [10-2]

= – ( –2)

pH​ = 2

12

 

What is the pH of a 0.000001M solution of HCl?

The number 0.0000001 is 10-6 (by moving the decimal point six places to the right), therefore:

 

pH = – log [H3O+]

= – log [10-6]

= – ( –6)

pH​ = 6

13

 

What is the pH of a 0.01M solution of NaOH?

Since NaOH is a base, we are going to start from the basic end of the pH Scale.

0.01M is 10-2 

Starting from the very basic 14, we subtract 2 to get the pH.

 

pH = 12