How To Name Transition Metals

Naming Compounds

More than Practice With Naming

Before naming a compound, yous accept to figure out what kind of compound information technology is. We will consider three types:

Ionic Compounds Without a Transition Metal .

Ionic compounds are formed when a metal gives up its electrons to a non-metal. Basically if the chemical compound contains a metal, it is ionic. Merely at that place are unlike sets of rules for transition metals. A� transition element is an element with an atomic number of 21 to 30, 39 to 48 or 57 to fourscore.

a.�� So for a compound with whatever other metal, apply these rules:

The metal ion's name does non change regardless of charge
The non-metallic's proper noun ends in ide.

For case: �� AlCl_three = aluminum chlor ide

�� Na_twoS = sodium sulf ide

_{��} Thou₂O = potassium oxide

�� MgH₂ = magnesium hydride

Notice how the little numbers (subscripts) do not affect the style nosotros name them.

b.�� In going backwards (from name to formula), we volition have more fun. In such a example the total accuse of the (+) and (-) ions in the compound has to be Zero.

Case : What is the right formula for calcium phosphide?

Hither, we have to consider the mutual charges for calcium and phosphorus, which are +two and -3, respectively. Calcium, if you recall, typically loses two electrons to become a noble gas electron arrangement, and phosphorus needs three more than electrons.

�� Ca⁺² and P^-3

_{��} One of each would create a sum of 2 + (-3) = -ane. To get a sum of zip, we demand three Ca⁺² ions and 2 P^-3for a total of three(2)+ 2(-iii) = 0.

Then the reply is Ca₃P_two.

Other examples :�� potassium oxide :�� K^+one and O^-2 � give K₂O

_{�� } aluminum bromide�� Al⁺³ and Br^-1 yield AlBr_three.

c.�� Polyatomic Ions

When metals are bonded to polyatomic ions, which consist of two or more atoms with one overall charge, the same rules apply, only you accept to larn the names and charges of common polyatomic ions.

Polyatomic Ion	Name
OH^-i	hydroxide
SO_iv ^-2	sulfate
PO₄ ^-iii	phosphate
NO_three ^-one	nitrate
CO₃ ^-2	carbonate
HCO₃ ^-1	hydrogen carbonate or bicarbonate
ClO₃ ^-i	chlorate
NH₄ ^+one	ammonium

Na_iiCO₃ = sodium carbonate. ( This is a useful chemical in purifying others; it is sometimes called washing soda)

KNO₃ = potassium nitrate ( This is an ingredient of gunpowder and it is too found in fertilizer.)

To go backwards:

Aluminum sulfate

This has Al⁺³ and so₄ ^-2. To get a sum accuse of Zippo, nosotros need two aluminum ions and three sulfates, so the formula becomes Al₂(And then_iv)₃. Notice that when at that place is more than than i polyatomic group, we brand use of brackets.

ii. Ionic Compounds With a Transition element .

The simply difference here is that nosotros accept to specify the charge of the transition metal ion past using a Roman numeral, and keep in mind that a transition element is an element with an diminutive number of 21 to 30, 39 to 48 or 57 to fourscore.

Roman numeral	Charge
I	+i
2	+2
III	+3
Four	+iv
5	+5
Half dozen	+6

The reason we do this is not for the sake of nostalgia for foretime Roman numerals nor to imitate film credits. Because transition metals can assume more 1 charge, we have to specify which one is involved

Example :�� manganese(Two) oxide contains Mn⁺²and O^-2. Then nosotros just demand i of each and the formula becomes MnO.

�� Copper(I) oxide is Cu_iiO.

To go backwards, nosotros need to figure out the charge of the transition metallic.

Case : What is the right name of� CrCl_three ?

�The accuse of Cr is unknown = 10 . Simply chloride = (-one). The sum of the charges has acme be nil, and then:

�� 10 +3(-one) = 0.

�� ten = 3.

Answer:�� CrCl₃ = chromium (III) chloride.

3. Covalent Compounds . These are formed from non-metals that share electrons. Because there are many sharing possibilities between ii not-metals, the formula cannot exist guessed unless we have a naming system that reveals the number of atoms involved.

For this we utilise a set of prefixes:

�

Prefix	Number of atoms
mono	1
di	2
tri	3
tetra	4
penta	5
hexa	half dozen

The only time nosotros drop a prefix is if the mono is to announced at the beginning of the name.

Examples: �� CO = carbon monoxide ( note we don't say monocarbon monoxide)

�� CO_ii = carbon dioxide

�� dinitrogen pentoxide = N_twoO₅.

�� phosphorus trichloride PCl_three.

Note that none of the above compounds contain a metal. Metals do not course covalent compounds, so we generally don't employ prefixes for compounds containing metals.

Summary:

More Practice With Naming

ane. Name the following:

a. NaOH b. Li₂South c. FeCl_three (430 just) d. H₂O e. K₃N f. CaSO_iv

two. Write formulae for the post-obit:

a. beryllium chloride b. copper (I) oxide (430 only) c. diphosphorus pentoxide d. aluminum carbonate east. ammonium phosphate f. sulfur dioxide

Answers
i. a. sodium hydroxide b. lithium sulfide c. iron(III)chloride d. dihydrogen monoxide e. potassium nitride f. calcium sulphate
2. a. BeCl₂ b. Cu₂O c. P₂O₅ d. Al₂(CO_three)₃ e. (NH_four)₃PO₄ f. And then₂