Chapter 6: Textbook Flashcards
Would a solution of molecular compound be acidic, basic or neutral?
Neutral
Would a solution of Ionic compound be acidic, basic or neutral?
Neutral
What did Svante Arrhenius say about acids and bases?
Acids are substances that ionize in aqueous solutions to to form hydrogen ions, and bases are substances that dissociate to form hydroxide ions in aqueous solutions
What are properties of acidic solutions related to?
Hydrogen Ions
What are properties of basic solutions related to?
Hydrocide ions
What is the chemical formula for the hydronium ion?
H3O+
Why is the hydronium ion created?
When an acid dissolves in water the h+ ion bonds with H2O
Who invented the hydronium ion?
Paul Giguere
What does a modern view of of the nature of solutions say about acids?
Hydronium ions are responsible for acidic properties
What is use to measure the strengths of acids or bases?
A pH meter
What causes an acidic solution to become more acidic?
The greater the concentration of hydronium ions
What causes a basic solution to become more acidic?
The greater the concentrations of hydroxide ions
Why does neutral water always contain trace amounts of both hydronium and hydroxide ions?
This is due to very slight ionization. About 2 out of every billion molecular collisions form hydronium and hydroxide ions
In pure water at SATP what is the concentration of hydronium ions?
Very low. Often negligible. Conductivity tests show that no conductivity
What is the concentration of hydronium ions in aqueous solutions?
There is a very wide range
What type of solutions containing hydronium ions can be considered acidic, basic, or neutral?
Any solution containing hydronium ions can be classified as acidic basic or neutral
What is the concentration of hydronium ions in a neutral solution?
[H3O+(aq)] = 1 x 10^-7 mol/L
What is the concentration of hydronium ions in a acidic solution?
[H3O+(aq)] >1 x 10^-7 mol/L
What is the concentration of hydronium ions in a basic solution?
[H3O+(aq)] < 1 x 10^-7 mol/L
Who produced the term pH or power of hydrogen?
Soren Sorensen
What is the pH of a solution defined as?
The negative of the exponent to the base ten of the hydronium ion concentration. ex 10^-7 has a pH of 7
When is defining the pH of solution based on their negative exponents convenient?
When the negative exponent is a whole number, which i rarely the case
What are acid base indicators?
Substances that change color when the acidity of a solution changes
What is litmus paper obtained from?
Lichen
What are the 3 common acid base indicators?
Litmus paper Lt
Bromothymol blue Bb
Phenolphthalein In
What do the forms of an acid base indicator depend on?
Weather a particular hydrogen atom is present in the indicators molecule
What is the lower pH form of an indicator called?
HIn(aq)
What is the higher pH form of an indicator called?
In-(aq)
What pH levels does litmus papers usually change colors between?
6.0 - 8.0 Between these pH’s you will see mixtures of red and blue
What are the 2 primary uses of acid base indicators?
- To mark the end of titration
- To estimate the pH of a solution
What is bromothymol blue paper used for?
To test aquarium water pH values between 6.0 and 7.6
What is the precision of bromothymol blue paper? and why?
The precision is to about 0.1 pH unit. Because of the subtle differences in color that can be compared toa chart
What does the formation of a hydronium ion mean?
That there is a reaction with an H+ ion and water molecules
What are acids according to Arrhenius theory?
Acids are substances that react with water to produce hydronium ions
Why is ammonia considered a base?
Because it reacts with water molecules to produce hydroxide ions
What are bases according to Arrhenius theory?
Substances that react with water to produce hydroxide ions
What type of reaction is neutralization?
A double replacement reaction
According to Arrhenius theory what happens when we mix an acid and base?
H3O+ + OH- = 2 H2O
What can neutralization be defined as?
The reaction between hydronium and hydroxide ions to produce water
What is important when comparing acid strengths?
The concentration and temperature be controlled
When is an acid described as a weak acid?
When its characteristic properties under the same conditions are less than those of a common strong acid
What are the most common strong acids?
Hydrochloric
Sulfuric
Nitric
What idea would be consistent with strong acids?
That they react completely with water to form hydronium ions
What properties does a strong acid have?
- High concentration of H+ to react with H2O
- High conductivity
- High rate of reaction with metals
- Low pH
What properties do weak acids have?
- An acid with a low conductivity
- A low rate of reaction with metals
- A high pH
- H+ does not react completely with H2O
What is an example of a strong base? Weak base?
Sodium Hydroxide
Ammonia
What are the characteristics of a strong base?
- High conductivity
- High base
What are the characteristics of a weak base?
- Low conductivity
- Low pH
How can the behavior of strong bases be explained?
Dissociation with increased hydroxide ion concentration
What are all soluble ionic hydroxides?
Strong bases because 100% of hydroxide ions dissociate
What are properties of weak bases?
Bases like NH4 do not contain hydroxide ions but they do contain hydroxide ions in a stronger concentration than pure water
How does a weak base react with water?
They react partially with water to produce relatively few hydroxide ions
What are monoprotic acids?
Acids with only one hydrogen atom and can only react with hydrogen once
What are polyprotic acids?
Acids that contain more than one acidic hydrogen atoms and can react more than one with water
In polyprotic reactions how is the reaction affected with each reaction with water?
The reaction decreases with each reaction