4.2.2 Acid-Base Reactions Flashcards
Acid-Base Reactions
- Arrhenius acids increase H+concentration in a solution; strong acids dissociate completely in water, whereas weak acids dissociate only partially.
- Arrhenius bases increase OH–concentration in a solution; strong bases dissociate completely in water, whereas weak bases “dissociate” only partially.
- A Lewis acid or base does not have to have a H+ or OH–- to generate these ions in water.
- A pH indicator changes color with changing amounts of H+ or OH– ions and can be used to demonstrate that acids and bases react together in a neutralization reaction to form water and a salt.
note
- An Arrhenius acid is any compound that increases H+ concentration in a solution.
- Strong acids, such as hydrochloric acid, completely dissociate in water.
- Weak acids, such as acetic acid, only partially dissociate in water.
- An Arrhenius base is any compound that increases OH– concentration in a solution.
- Strong bases, such as sodium hydroxide, dissociate completely in water.
- Weak bases only partially “dissociate” in water. A Lewis acid or base does not have to have a H+ or OH– to generate these ions in water.
- The weak base ammonia does not contain OH– but causes its production when dissolved in water.
- The weak acid carbon dioxide does not contain H+but causes its production when dissolved in water.
- A pH indicator changes color with changing amounts of H+ and OH– caused by the presence of an acid or a base.
- An indicator can be used to observe acids and bases reacting together. Acids and bases react together in a neutralization reaction in which water and a salt are produced.
Suppose 200 mL of a 0.001 M solution of NaOH is combined with 300 mL of a 0.002 M solution of HCl. How many moles of hydrogen ions does the final solution contain?
4 × 10^−4 mole H +
a solution of an acid is mixed with a solution of a base. the neutral mixture that results contains magnesium nitrate (Mg(NO3)2). this mixture could have resulted from the combination of which of these pairs of solutions
a solution of Mg(OH)2 and a solution of HNO3
What is the total ionic equation for a reaction between a solution of sodium hydroxide (NaOH) and a solution of perchloric acid (HClO4 )?
Na+ + OH − + ClO4− + H + → Na+ + ClO4− + H2O
The acidity of blood must be kept within a very narrow range or serious medical problems and even death can result. Suppose a person’s breathing becomes slow and shallow. Less oxygen (O2 ) is inhaled and less carbon dioxide (CO2 ) is exhaled, causing the oxygen level in the blood to fall and the carbon dioxide level to rise. What effect will this situation have on the blood’s acidity?
The acidity will increase as a result of the greater amount of CO2.
Methyl red is an acid-base indicator. It turns red in strongly acidic aqueous solutions and yellow in all other aqueous solutions. Suppose methyl red turns an aqueous solution yellow. A second solution is added to the first solution. This mixture remains yellow no matter how much of the second solution is added. What can you conclude about the second solution?
It does not contain a strong acid.
Which of these compounds is an acid in aqueous solution?
H2SO4
Sulfur dioxide (SO2 ) is a weak acid (a Lewis acid). Which of these reactions will occur when sulfur dioxide gas dissolves in water?
SO2 + H2 O → HSO3 − + H +
You have two colorless aqueous solutions, X and Y. You also have an indicator that turns purple in basic solutions, green in neutral solutions, and red in acidic solutions. Solution X turns purple when you add a small amount of the indicator to it. When you then add 5 mL of Solution Y to Solution X, the resulting mixture turns green. What can you conclude about Solution Y?
It is acidic.
Is ammonia, NH3, in water an acid or a base? Why?
It is a base. Ammonia reacts with water to produce hydroxide ions.
Which of these aqueous solutions is likely to be the best electrical conductor?
a 0.10 M solution of hydrochloric acid, HCl
