Chemistry Titration

what are the five properties of acids?

1. Sour taste

2. turns blue litmus paper red

3. some react with metals to produce hydrogen gas (H2)

4. reacts with bases to produce salt and water

5. acids conduct electric current

what are the five properties of bases?

1. tastes bitter

2. turns red litmus paper blue

3. slippery

4. reacts with acids to produce salt water

5. bases conduct electric current

What are the two common types of acids that exist?

binary acids and oxyacids

A binary acid contains hydrogen and one other element. In order to name a binary acid what are the steps?

1. the first word begins with hydro and the root of the second element plus the suffix -ic

2. the second word is always “acid”

3. Format should be hydro blank ic acid

An oxyacid contains a hydrogen atom and an oxyanion: a polyatomic ion containing one or more oxygen atoms. In order to name an oxyacid what are the steps?

1. Identify the polyatomic ion present.

2. the first word of an oxyacid’s name consists of the root of the oxyanion and the prefix “per-” or “hypo” if that is part of the name.

3. Add a suffix: REMEMBER ate-ic and ite-ous

4. the second word is always acid

How much does a strong acid ionize in a solution?

A strong acid ionizes completely in a solution.

Is a strong acid a strong electrolyte?

yes

What is the correlation between acid strength, polarity, and bond energy?

When polarity INCREASES acid strength also INCREASES, while bond energy DECREASES

How much does a weak acid dissociate in a water solution?

A weak acid only slightly dissociates in a water solution.

What percent of WEAK acid molecules donate their hydrogen?

Only a small percent donates their hydrogen, and most remains the same

Which groups on the periodic table contains strong bases?

all oxides and hydroxides of group 1 and 2.

Which acids are the only binary acids that are strong?

HCl, HBr, and HI. All other binary acids are weak

What is the general rule of thumb for strong oxyacids?

Ratio of O to H is 2 or greater. For example, H2SO4.

How do you determine between a strong acid and weak acid in a lab?

1. Use a conductivity apparatus test.

2. Measure conductivity of solutions.

3. React the two acids with a metal like magnesium.

4. Measure the ph of the solutions using a ph meter or indicators.

How do you determine between a strong base and weak base in a lab?

1. Use a conductivity apparatus test.

2. Measure conductivity of solutions.

3. React the two bases with a chemical and observe the rate of reaction.

4. Measure the ph of the solutions using a ph meter or indicators.

What is true about hydroxides and hydronium ions?

All water solutions contain H+ and OH ions. Water self ionizes to form hydronium ions and hydroxide ions. Hydronium ion is a hydrogen ion covalently bonded to a water molecule - more stable

What role does an arrhenius acid play in a reaction?

An arrhenius acid produces hydrogen ions

What role does an arrhenius base play in a reaction?

An arrhenius base is an OH producer.

In a bronsted lowry model, what role do the acid and base play in relation to each other?

Acid is H+donor and the base is an H+ acceptor.

In a Lewis model, what role do the acid and base play in a reaction?

The acid ACCEPTS an electron whereas the base donates an electron.

What is true of the pH of acidic, basic, and neutral solutions at 298K?

At 298K acidic solutions have pH values below. Basic solutions have pH values above 7. Neutral solutions have a pH value of 7.

What is true of the pOH of acidic, basic, and neutral solutions at 298K?

At 298K basic solutions have a pOH less than 7, a solution with a pOH of 7 is neutral, and a solution with a pOH greater than 7 is acidic.

What is the Net equation for acid/base neutralization?

H3O+(aq) + OH-(aq) →2H2O(l)

What can be used to compare concentrations of acids and bases?

Since acids and bases react, a progressive addition of acid to base or base to acid can be used to compare concentrations of acids and bases. This is why titration is important.

what is a titration?

a method for finding the concentration of a solution by reacting a known volume of that solution with a solution of another known concentration.

What are the steps of a titration?

1. a measured volume of an acidic or basic solution with no knowledge of its concentration is placed in a beaker.

2. a buret is filled with a titration solution of the known concentration. This is called the titrant, or the standard solution.

3. Standard solution is gradually increased into the beaker, which continues until it reaches equilibrium.

What is the equivalence point?

a point at which moles of H+ in from the acid equal moles of OH- ion from the base. ( points end up overlapping vertically)

REMINDER

Equivalence point does not mean the solution has a pH of 7

What are the different indicators for finding titration?

1. indicators with a pH<7 are used for strong-acid/weak-base titrations.

2. indicators with a pH>7 are used for weak acid/strong base titrations

3. there are no specific indicators used for weak acid/weak base titration because the equivalence point can be almost an value.

What is true of the titrant in relation to a weak acid solution versus a strong acid solution?

It takes less titrant to change the PH of a weaker acid solution than that of a strong acid solution.

adding more base…

quickly increases the pH

what is equivalence point?

this is the point where all the acid has reacted with the base, such that further additions of base quickly raise the pH

What is the equivalence point for a strong and weak acidbase titration?

1. strong acid strong base titration has a pH of 7

2. weak acid strong base titration has a pH of less than 7

What is an acid base indicator?

they are chemical dyes whos colors are affected by acidic or basic solutions, and whose color changes as pH changes. It is helpful since it gives an estimated value for pH of a solution.

Many indicators are weak acids with own pH range over which it changes colors-

u need to use indicator that changes color at EQUIVALENCE point of titration

What is transition interval?

pH range over which an indicator changes color

What colors are used to titrate different acid/bases?

1. To titrate a strong acid/base - use brothymol blue

2. to titrate a strong acid weak base - use Methyl orange (pH change <7)

3. To titrate a weak acid/strong base - use phenopthalein or phenol red (pH change > 7)

4. Universal indicator mix of several indicators, used for pH paper

what is the end point?

point in titration where neutralization has occurred and the indicator changes color or there is a dramatic change in pH.

what does a pH meter do?

1. determines exact pH by measuring voltage differences between 2 electrodes in a solution

2. Voltage changes as (H3O) changes, used if exact pH value is needed