Unit 5 Lesson 6 Chemistry A: The Laws Governing Formulas and Names
Generally, what does an -ide indicate?
It is a binary compound
What does -ate indicate?
It is an polyatomic ion that includes oxygen in the formula.
What does an -ite ending indicate?
It is an polyatomic ion that includes oxygen in the formula.
What do you know if the cation is hydrogen?
then the compound is an acid > http://ocas.pearsonschool.com/ph/cd/0-13-190443-4/ebook/products/0-13-190443-4/view1_chem05_fig9_20.pdf < for book flowchart
What are the endings of the names of most polyatomic anions?
-ite or -ate.
Naming Molecular Compounds
1)Make sure that it has two nonmetals (thus, is a binary molecular compound in the first place) 2)Name elements in order listed in the formula. 3) Use prefixes to indicate the number of each kind of atom. 3A) Omit mono- when the formula contains only one atom of the first element in the name. 4) The suffix of the name of the second element is -ide.
What is a monatomic ion?
A single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons.
Why must their proportions by mass always be the same?
Because atoms combine in simple whole-number ratios.
How do you name an acid with an ending of -ide?
Change the -ide to -ic and add the prefix hydro-
Why is naming and writing formulas for compounds possible?
Compounds form from the elements in predictable ways.
When you have two possible charges for an anion or cation, how do you know which one to use to balance the formula?
Look at the ratio in which they combine. Then look at the other cation or anion in which doesn't have more than one. What is the charge it has? Balance that charge, with the two options you have. For instance, if the charge of an anion is 2-, then the charge you pick for the cation will be 2+. In CuO, Oxygen's charge is 2-, Cu's possible charges are + and 2+. Pick 2+ to balance the charge. So its copper (II) oxide.
if how the compound is formed changes or if the size of the sample changes, is the mass ratio changed?
No.
If a prefix is in the name of a compound, generally, what can you conclude?
The compound is molecular.
What does a roman numeral after the name of the cation indicate?
The ionic charge of the cation.
What are ways in which compounds form from the elements in predictable ways?
The law of definite proportions, and the law of multiple proportions
How would you name an anion?
The name starts with the stem of the element name and ends in -ide.
When do you use parentheses in a formula?
When the compound contains more than one polyatomic ion.
How would you write the formula for an ionic compound with a polyatomic ion?
Write the symbol for the cation+Write the formula for the polyatomic ion Then balance the charges.
When naming acids with anions ending in -ate, what do you do?
You change the -ate to *-ic* & *keep any prefixes the anion* may have. When naming acids with anions ending in -ite, what do you do? change -ite to -ous. *keep any prefixes the anion* may have.
For an ion that a *nonmetal of Group A*, how would to determine the charge?
You would subtract 8 from the group A number.
binary ionic compounds
composed of the ions of two elements: a metal and nonmetal
What is an binary compound?
composed of two elements and can be either ionic or molecular.
binary molecular compounds
composed of two elements which are two nonmetals (they are not ions)
when elements combine ionically, what do they form?
crystal structures (not molecules)
Cl2O8
dichlorine octoxide
The law of definite proportions
in samples of any chemical compound, the masses of elements are always in the same proportions
If the name doesn't contain prefixes, what do you know?
it is ionic
what do all anions with names ending in -ite and -ate contain?
oxygen.
The mass ratio of oxygen to hydrogen is always the (same/different).
same
mono
the presence of one oxygen atom
di
the presence of two oxygen atoms
how does the a chemical formula express the ratio of atoms of each element in the compound?
via subscripts.
The Law of Multiple Proportions
whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers. > https://www.youtube.com/watch?v=aC_tIVGCb9E < this made it make sense
