 Warm Up 4/14 How many protons and neutrons would an H+ ion have?

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Warm Up 4/14 How many protons and neutrons would an H+ ion have?

AcidsBases Definitions Neutralization Strong vs Weak Litmus Paper

Common Acids

Properties of Acids - Corrosive (burns skin and “eats” metals) - Sour taste - Turns blue litmus paper red - Electrolyte -pH less than 7

Common Bases

Properties of Bases -Caustic (leaves a white residue on metals) -Bitter taste -Slippery feeling -Turns red litmus blue -Electrolyte -pH greater than 7

Arrhenius Acid: a solution made of any solute with hydrogen (H + ) as its cation. Base: a solution of any ionic salt with hydroxide (OH - ) as its anion.

Bronsted Acid: molecule or ion that is a proton (H + ) donor Base: a molecule or ion that is a proton acceptor

Neutralization Reaction – When an acid and base react to form a neutral solution (water and a salt). Examples: NaOH + HCl → H 2 O + NaCl 2NaOH + H 2 SO 4 → 2H 2 O + Na 2 SO 4

Acids and bases can be classified as weak or strong. Strong acid/base- ionizes (dissociates) completely ex.: HCl + H 2 O → H + (aq) + Cl - (aq)

Weak acid/base- only ionizes (dissociates) partially ex.: HF + H 2 O → H + (aq) + F - (aq) + HF

Warm Up 3/26 Give the salt that will be formed in the following neutralization reaction: 2 HBr + Ba(OH) 4 → 2 H 2 O + ___?___

pH stands for “power of hydronium” Hydronium is H 3 O+ (it is the correct way to write the formula of a H+ ion that has been donated in water) pH Scale

Acids have a pH less than 7 7 is neutral Bases have a pH higher than 7 Each step on the pH scale is a step of 10

Calculating pH pH or “power of hydronium” is based on the concentration of H 3 O + ions H 3 O + is another way to write H + Formula: pH = -log [H + ]

Calculator Steps 1)Press the (-) button (not the minus sign button!) 2)Press the Log button 3)Enter the concentration and close the parenthesis

Example #1 Calculate the pH of a solution whose [H + ] = 1.0 x 10 -4

Example #2 Calculate the pH of a solution whose [H + ] = 3.1 x 10 -4

Left Side Practice Find the pH of these concentrations of H+, and tell whether it’s an acid or a base. 1) [H + ] = 1.0 ×10 −6 M 2) [H + ] = 2.19 ×10 −4 M 3) [H + ] = 9.18 ×10 −11 M 4) [H + ] = 4.71 ×10 −7 M 5) [H + ] = 1.0 M

Lesson: pH Calculations

K = [H + ][OH - ] = 1.0 ×10 −14 w Ionization Constant of Water: (We will be using this in our calculations)

Finding pH from [OH - ] Divide 1.0 ×10 −14 by the [OH - ] concentration. Then solve like a regular H+ problem: -log [H + ] Example: Calculate the pH of a solution with an [OH - ] of 1.0 ×10 −3.

pOH Calculations Formula: pOH = -log [OH - ] If given the [OH - ], then just put that number in the parenthesis. If given the [H + ], then divide it by 1.0 ×10 −14 and put the answer in the parenthesis.

Example: Calculate the pOH of a solution with an [OH - ] of 2.7×10 −4. Example: Calculate the pOH of a solution with an [H + ] of 9.18 ×10 −11.

To go from pH back to [H + ] (or from pOH back to [OH - ]) just put in: 10^- given Example: Calculate the [H + ] of a solution whose pH = 6.3

Calculating pOH pOH or “power of hydroxide ion” Formula: pOH = -log [OH - ]

Example #3 What is the pH of a 0.250M solution of KOH?

Example Problem #4 Calculate the pH and pOH of a 0.315M H 2 SO 4 solution.

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