Chemistry Ion Chips Worksheet #2

Acids – Formulas and Nomenclature –

In acidic compounds, hydrogen behaves as a metallic ion with a positive charge – and bonds to negative nonmetals as well as to negative complex ions. As with ionic compounds, the charges in acids must be balanced to result in a net charge of zero. If a polyatomic ion is involved (SO42-, PO43-, etc), it does not require parentheses, as enough hydrogen is added to balance the formula – H2SO4 (aq). The sulfate ion has its 2- charge canceled out by the addition of two hydrogen. H+2 SO42-

Acids are not ionic, even though they behave in a similar manner with charges and form conducting solutions. Remember – due to canceling out charges, you do not need or use number prefixes in the name of acidic compounds!

For this exercise, fit your chips together to create electronically balanced compounds. Use the red hydrogen to represent “acid – forming” hydrogen. Your chips also have another hydrogen chip of some colour other than red – treat this as a “complex ion hydrogen addition”. Write the correct formula/name in the space provided – pay attention to subscripts! Polyatomic or “complex” ions can be found in the central chart on your periodic table of ions. (Notice the little mini-box of info…check it out! J)

General Rule of Thumb: “ide” means single ion; “ate” or “ite” means complex. Exception – hydroxide and cyanide are complex.

* Be aware of the “changing oxygen” numbers possible within complex ions – watch for prefixes such as per -, or hypo -, or endings such as –ite. Alter your formula accordingly. Remember that the charge does not change with the loss or gain of oxygen.

Other items to take note of…

1. Oxy acids that have a “___COO_” structure have the hydrogen attaching at the end of the COO- part. This applies to complex ions such as acetate, benzoate, oxalate etc. Acetic acid = CH3COOH (aq)

2. If a hydrogen substance is NOT aqueous – do not name it as an acid! Name it according to its composition. For example – HCl (g) is hydrogen chloride gas; not an acid named hydrochloric acid!

3. Both sulfur and phosphorus keep their respective “ur” and “or” syllables when dropping the “ate” in changing to an acid name – sulfuric, not sulfic; phosphoric, not phosphic…

4. All acid formulas must be followed by the subscript (aq). Aqueous means that it has dissolved in water, or is water-soluble.

5. Acids form through hydrogen ions (H+); bases form through hydroxide ions (OH -) – more on this later on! J

1 / Hydrochloric acid / 21 / H2SiO2 (aq)
2 / Hydrobromic acid / 22 / H3BO3 (aq)
3 / Hydrocyanic acid / 23 / H2SO3 (aq)
4 / Hydrosulfuric acid / 24 / HCN (g)
5 / Sulfuric acid / 25 / HI (aq)
6 / Phosphoric acid / 26 / H3P (aq)
7 / Nitric acid / 27 / HSCN (aq)
8 / Nitrous acid / 28 / HClO4 (aq)
9 / Hyponitrous acid / 29 / H2B4O7 (aq)
10 / Acetic acid / 30 / H2CrO4 (aq)
11 / Silicic acid / 31 / H2O (l)
12 / Oxalic acid / 32 / H2 (g)
13 / Stearic acid / 33 / H2CO3 (aq)
14 / Phosphorous acid / 34 / HF (aq)
15 / Chlorous acid / 35 / HMnO4 (aq)
16 / Carbonous acid / 36 / H5P3010(aq)
17 / Iodic acid / 37 / H2Cr207(aq)
18 / Glutamic acid / 38 / H3PO5 (aq)
19 / Hypocarbonous acid / 39 / H3BO2 (aq)
20 / Benzoic acid / 40 / H2Se (aq)

Testing Your Knowledge of Acids and Bases J

Answer T (true) or F (false) to each of the following statements –

1. _____ Acids will not conduct an electrical current.

2. _____ Acids will turn litmus paper red.

3. _____ Acids taste bitter.

4. _____ Acids neutralize bases.

5. _____ Bases taste sour.

6. _____ Bases feel slippery when they contact your skin.

7. _____ Bases neutralize acids.

8. _____ Bases will turn a litmus solution red.

9. _____ Acids react with some metals to produce hydrogen gas.

10. _____ Citrus fruits contain acids.

11. _____ Vinegar contains bases.

12. _____ Soaps contain acids.

13. _____ Red cabbage juice can be used as an acid-base indicator.

14. _____ An indicator is a substance that only reacts to acids not bases.

15. _____ Vinegar is acetic acid.

16. _____ Acetic acid has no colour and smells quite sharp.

17. _____ Some medicinal compounds help to neutralize stomach acids.

18. _____ Acids dissolve many metals.

19. _____ Sour milk is an acid.

20. _____ Sink drain cleaners contain strong bases.

21. _____ Bee stings contain acids, while wasp stings contain bases.