acid
a compound that releases hydrogen ions, H+, in aqueous solution
strong acid
an acid that dissociates completely in aqueous solution
What are characteritics of acid?
1. Sour taste
2. Shows a characteristic color change with indicators such as litmus
3. Its chemical properties. For example, under certain conditions acids can react with marble, eggshell, or the shells of marine creatures, causing them to dissolve
What is the effect of gases like SO2 and NO2 dissolving in water to produce acidic solutions?
SO2 and NO2, two gases emitted during the combustion of certain fuels (particularly coal) to produce heat and electricity, both dissolve in rain and mist. When they do so, they form acids that in turn fall back to the Earth's surface in rain and snow.
Given that an acid is defined as a substance that releases hydrogen ions in water, how can carbon dioxide act as an acid?
The explanation is that when CO2 dissolves in water, it produces carbonic acid, H2CO3(aq).The carbonic acid dissociates to produce the H+ ion and the hydrogen carbonate ion. This reaction occurs only to a limited extent, producing only tiny amounts of H+
weak acid
an acid that dissociates only to a small extent in aqueous solution
base
a compound that releases hydroxide ions, OH?, in aqueous solution.
What are some characteristics of a base?
1. Generally taste bitter and do not lend an appealing flavor to foods.
2. Aqueous solutions of bases have a slippery, soapy feel.
strong bases
Bases that dissociate completely in water
weak base
a base that dissociates only to a small extent in aqueous solution.
neutralization reaction
a chemical reaction in which the hydrogen ions from an acid combine with the hydroxide ions from a base to form water molecules.
If there are no oxygens in an acidic formula:
hydro____ic acid
ex. H2S(aq)= hydrosulfuric acid
If a polyatomic ion is present in an acidic formula and ends with "ite":
hydro____ous acid
ex. HNO2(aq)= nitrous acid
If a polyatomic ion is present in an acidic formula and ends with "ate":
hydro____ic acid
ex. H2SO4(aq)= sulfuric acid
Give the chemical name for HNO3
nitric acid
("ate"="ic")
Give the chemical name for the aqueous solution that forms when HF gas dissolves in water
hydroflouric acid
Give the chemical name for NaOH
sodium hydroxide
Some gases are soluble enough in water to dissolve to produce an acidic solution, although in some cases only slightly so. Which gas can dissolve in water to produce H2SO4(aq)?
SO3. (Remember, that water adds two hydrogens and one oxygen to the gas in forming the acid.)
Aqueous solutions of nitric acid (HNO3) and potassium hydroxide (KOH) neutralize each other to produce a compund. Give the chemical formulas of the anion and cation in the compund produced.
HNO3(aq) + KOH(aq)---> H-OH(l) + KNO3(aq)
Cation: K+
Anion: NO3-
pH
a number, usually between 0 and 14, that indicates the acidity (or basicity) of a solution.
What is the pH range for an acid?
0-6
What is the pH range for an base?
8-14
What is the pH range for a neutral solution?
7. Solutions of pH 7 (such as pure water) have equal concentrations of H+ and OH- and are said to be neutral.
What mathematical equation is used in order to find the pH value of a solution? What does it mean?
pH = ?log [H+]
A pH value is simply a special case of a logarithmic relationship. It is defined as the negative of the logarithm of the H+ concentration, expressed in units of molarity (M). Square brackets are used to indicate molar concentrations.The neg
Calculate the pH of a beverage with a hydrogen ion concentration of 0.000546 M
pH = ?log [H+]= -log (5.46 x 10^-4 M)= pH level of 3.26
Calculate the pH of milk with a hydrogen ion concentration of 2.20 � 10^-7 M.
pH = ?log [H+]= -log (2.20 � 10^-7 M)= pH level of 6.66
acid rain
rain with a pH below 5 that is more acidic than "normal" rain
What is the natural pH range for rain?
Rain naturally has a pH between 5 and 6
How is NOx related to acid rain?
Nitrogen oxides also dissolve in water to form acids, but the chemical reactions are more complex because the element O2 also is a reactant. For example, NO2 reacts in moist air to form nitric acid.In water, nitric acid dissociates to release H+.The nitra
acid deposition refers to...
both wet and dry forms of delivery of acids from the upper atmosphere to the surface of the Earth. Examples of wet deposition include rain, snow, and fog.
What are 2 ways in which NOx forms?
1. In an automobile, gasoline and air are drawn into the cylinders and compressed, bringing the N2 and O2 molecules closer together.The gasoline, once ignited, burns rapidly.
2. The same reaction occurs when air is heated in the furnace of a coal-fired el
The hydrogen ion concentration multiplied by the hydroxide ion concentration forms the constant:
[H+][OH-]=1 � 10?14