Unit 1 Second half unit test Flashcards
Roman Numerals 1 to 10
I
II
III
IV
V
VI
VII
VIII
IX
X
Prefixes for molecular bonds
mono
di
tri
tetra
penta
hexa
hepta
octa
nona
deca
What is a polyatomic ion
Definition: a group of covalently bonded atoms that has a net charge (positive or negative) Also known as Radicals - group of atoms that tend to stay together during most chemical reactions
How to balance charges with multivalent atoms
Look at the charge(s) on the non-metal and add them. Find which charge balances with it
Adding Hydrogen (H+) to radicals
Adding H+ to radicals causes the
charge on the radical to change.
eg: CO3 (-2) + H(+)—-> HCO3 (-)
Hydrogen carbonate or bicarbonate
Adding oxygen to polyatomics
_____ates are the “standard”
_____ ates - 1 Oxygen = ______ ites
_____ ites - 1 Oxygen hypo____ite
_____ ates +1 oxygen = per______ate
What is gastric acid made of
Gastric acid, or stomach acid, is a digestive fluid, formed in the stomach and is composed of hydrochloric acid (HCl), potassium chloride (KCl) and sodium chloride (NaCl).
What are acids
Acids are covalent compounds that release hydrogen ions when added to water (aqueous). : HCl (aq) → (H+) + (Cl-)
The higher the concentration of hydrogen ions produced by an acid, the higher its acidity and the lower the pH of the solution.
2 types of acids: Binary acids (Hydrogen and another element) and Oxyacids (Hydrogen + Polyatomic ion that contains oxygen)
The H+ ion associated with the water molecule in the form of a hydronium ion, H3O+
How to name Binary acid
1) the prefix “hydro” is used.
2) the root of the anion is used.
3) the suffix “ic” is used.
4) the word “acid” is used as the second word in the name.
EG:
HF Hydrofluoric acid
HCl Hydrochloric acid
HBr Hydrobromic acid
Binary Acid are binary compounds of non-metals that produce H+ ions in aqueous solutions.
How to name Oxyacids
To begin, we need a point of reference.
1) The polyatomic ions ends in “ate” (NO3 -1 : nitrate) make the ___________-ic acids ( HNO3 : nitric acid)
2) The polyatomic ions ends in “-ite” called the ___________-ous acid. (HNO2 : nitrous acid), one less oxygen than the “ate” ion
3) The acid with one less oxygen than the “-ous” acid, it is called the hypo-____________-ous acid (HNO : hyponitrous acid)
4) The acid with one more oxygen than the “-ic” acid is called the per-_______-ic acid ( HNO4 : pernitric acid)
An oxyacid is an acid that contains an oxygen atom bonded to a hydrogen atom and at least one other non-metal
What is Acid ionization, Strong acids, and hydronium in humans
An acid’s strength refers to its degree of ionization.
Strong acids completely ionize (dissociate) in water, releasing all of their hydrogen ions while weak acids release only a portion, so it partially ionize.
The strength of an acid, and thus its corrosiveness, is determined by how much an acid ionizes into hydronium atoms in water.
The hydronium atoms (H3O+) chemically react with metals and living tissue. This corrosive property is useful in the human body, as the acid in the stomach aids in the digestion of food.
What is a strong acid
When an acid dissolves in water, a proton (hydrogen ion) is transferred to a water molecule to produce a hydronium ion and a negative ion depending on what acid you are starting from.
In the general case ..
HA +H2O ↔ H3O+ + A-
These reactions are all reversible, but in some cases, the acid is so good at giving away hydrogen ions that we can think of the reaction as being one-way. The acid is virtually 100% ionised.
For example, when hydrogen chloride dissolves in water to make hydrochloric acid, so little of the reverse reaction happens that we can write:
H2O(l) + HCl(g) → H3O+(aq) + Cl-(aq)
At any one time, virtually 100% of the hydrogen chloride will have reacted to produce hydroxonium ions and chloride ions. Hydrogen chloride is described as a strong acid.
A strong acid is one which is virtually 100% ionised in solution.
Other common strong acids include sulphuric acid and nitric acid.
What are weak acids
A weak acid is one which doesn’t ionise fully when it is dissolved in water.
Acetic acid is a typical weak acid. It reacts with water to produce hydronium ions and acetate ions, but the back reaction is more successful than the forward one. The ions react very easily to reform the acid and the water.
CH3COOH + H2O ↔ CH3COO- + H3O+
At any one time, only about 1% of the acetic acid molecules have converted into ions. The rest remain as simple ethanoic acid molecules.
HCl (aq) vs. H2CO3(aq)
Strong and weak vs concentrated and dilute acids
The strength of an acid is related to the proportion of it which has reacted with water to produce ions. The concentration tells you about how much of the original acid is dissolved in the solution.
It is perfectly possible to have a concentrated solution of a weak acid, or a dilute solution of a strong acid.
Physical properties of acids
sour taste (e.g. lemon – citric acid)
are soluble in water
turn blue litmus paper red
are corrosive
have pH values less than 7
conduct electricity
