Ionic Compound Formula Writing – Flashcards
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Unlock answers| A negative ion is called a(n) _____________. |
| Anion. |
| When atoms form cations, they (gain/lose) electrons. |
| Lose. |
| Explain the octet rule. |
| The octet rule states that atoms will gain or lose electrons so that they achieve a filled outer level of electrons. This is most often 8 electrons; hence the name octet rule. |
| What is the charge of the cation chromium(VI)? |
+6.
The Roman numeral indicates the charge. |
Which formula is correct for the compound copper(II) chloride?
A. Cu2Cl B. CuCl2 |
B is correct: CuCl2.
The Roman numeral does not indicate the number of copper ions. It indicates the charge of the copper ion. Since Cl has a -1 charge, you need two Cl- ions to balance one Cu+2 ion. |
| Write the formula (don't forget the charge);of the polyatomic ion sulfate. |
| SO42- |
A common positive polyatomic ion is named ammonium. ; Write its formula (don't forget the charge!) |
| NH41+ |
Write the formula of the ionic compound potassium nitrate. |
KNO3
No parentheses around the nitrate anion. Only use parentheses when the formula requires more than one polyatomic ion. |
Write the formula of the ionic compound ammonium oxide. |
| (NH4)2O |
Write the formula of the ionic compound iron(III) hydroxide. |
| Fe(OH)3 |
Write the formula of the ionic compound lead(IV) carbonate. |
| Pb(CO3)2 |
How many hydrogen atoms are in the compound aluminum tartrate? |
aluminum tartrate is Al2(C4H4O6)3.
There are 4 x 3 = 12 hydrogen atoms. |
| Write the formula for the compound lithium phosphate. |
| Li3PO4 |
| Name this compound: CoF2 |
Cobalt(II) fluoride.
Cobalt is one of those elements that requires a Roman numeral in its name. Check the back of your PT! |
| Name this compound: Ba(NO2)2 |
Barium nitrite.
(How do you know that barium does not require a Roman numeral?) |
One polyatomic not on your list is called permanganate.
A correct ionic formula containing this ion is Sr(MnO4)2. Based on this formula, what is the charge of the permanganate ion? |
| -1 charge, since Sr has a +2 charge and there are two permanganate ions for one strontium ion. |
| Name this compound: NH4Br |
| Ammonium bromide. |
What is incorrect about this ionic formula?
(Mg)Cl2 |
The ratio of ions is correct...what is wrong is the parentheses around the magnesium ion. Only use ( ) around polyatomic ions, and only when there is more than one polyatomic.
The correct formula is MgCl2. |
What is incorrect about this ionic formula?
Ca(SO4). |
The ratio of ions is correct...what is wrong is the parentheses around the sulfate ion. Only use ( ) around polyatomic ions when there is more than one of those ions in the formula.
The correct formula is CaSO4. |
| Write the formula for iron(III) bicarbonate. |
| Fe(HCO3)3 |
| Name this compound: Cu2SO3. |
| Copper(I) sulfite. |
| Name this compound: K3N. |
| Potassium nitride. |
What is wrong with this formula: SCa.
Also name this correctly-written compound. |
| The positive ion is always written first. The correct formula is CaS. Calcium sulfide. |
| Write the formula for silver acetate. |
AgC2H3O2.
No parentheses! |
