Chemistry Exam 6

Definitions

100

What measures the acid or base concentration in a water solution?

pH

200

What only looses some of its H⁺ ions

Example CH₃COOH

Weak acid

300

A diprotic acid releases how many H⁺ ions?

It releases 2 H⁺ ions

400

What is a triprotic base?

A base molecule that releases 3 OH^- ions

500

What is it called when we measure the concentration of an acid solution by gradually add a base to a solution until all of the acid is neutralized.

Titration

What does it pHmean

100

Give a pH number for a base.

A number greater than 7

200

What has a larger [H+]

pH 2  or pH 5

pH 2

300

If pH = 9, what does the [H+] =

[H+]= 10^-9

400

My [H+] = 10^-3  

What is my [OH^-] =?

[OH^-] = 10^-14-(-3)= 10^-11

500

If pH is 6, what is the pOH?

pH + pOH = 14

pOH = 8

pH Math

100

To Increase [H⁺] by 100 times.  

My pH number would go from 5 to _____

3   (increase H⁺ by 100 is 10².  So pH number decreases by 2)

200

If my pH goes from 9 to 12, 

My [OH^-] does what?

Increases by 10^(12-9)= 10³ = 1000  times

300

Bonus!  

Which prophet was teased for being bald?

Elisha. Reference: 2 Kings 2:23-25.

400

If I have 500 ml of 2 M HCl,

how many moles of H⁺ do I have?

Note: 2M means 2moles/Liter of HCl

500mL x (1L/1000mL) * 2moles/L =1 mole HCl

Every mole of HCL has 1 mole of H+

SO 1mole of H+

500

If I have 200mL of 3M NaOH,

How many moles of OH^- do I have

3M = 3moles NaOH / Liter NaOH

200mL x 1L/1000mL x 3moles/1Liter = 0.6 moles NaOH.  There is 1 mole of OH- in 1 moles of NaOH.  So I have 0,6 moles OH-

Equilibrium 1

100

What is Kw called?

The equilibrium constant of water

200

What value is K_w

K_w is the Equilibrium constant of water. It is 1x10^-14 = [H+][OH-] 

300

What is the Ka for

H₂SO₄ <--> 2H⁺ + SO₄^--

Ka = [2H⁺] [SO₄^--] / [H₂SO₄]

400

What is the Ka for 

H₃PO₄ <--> 3H⁺ + PO₄^-3

Ka = [H⁺]³ [PO₄^-3] / [H₃PO₄]

500

What is Kb for

NH₄OH <--> NH₄⁺ + OH^-

Kb = [NH₄⁺][OH^-]/[NH₄OH]

Equilibrium 2

100

What does Ksp stand for?

Solubility Product

200

What is the Ksp of

Ca(PO₄)₂ <--> 3Ca⁺⁺ + 2PO₄^-3

Ksp = [Ca⁺⁺]³[PO₄^-3]²

300

When you find Ksp what is not part of the equation? Bonus why?

The Reactants are not part of the equation. It's just the products.

The part that "settles" or precipitates out of the solution is not part of the solubility constant. 

400

In the equation

NH₄OH <--> NH4⁺ + OH^-

What happens if you take some NH4 out of the solution?

Some of the NH₄OH would break apart into NH₄⁺ and OH^-.  This would reduce the NH4OH and keep the system in equilibrium.

500

Why do we use titrations?

We use them to force the weak acids and bases to release all of the their H+ ions or OH- ions into the solution so that we can get an accurate concentration amount