Help with chemistry!?
1) A metal oxide reacts with an acid to give
a) Salt only
b) salt and carbon dioxide
c) salt and water
d) salt, water, and carbon dioxide
2) A weak acid is one which
a) contains hydrogen gas
b) is partially ionised in solution
c) contains hydroxide ions
d) is fully ionised in solution
3) Which one of the following compunds is amphoteric?
a) sulphur dioxide
b) lead (II) oxide
c) sodium oxide
d) lead (II) chloride
Thanks.=)
Answer:
1) such as CaO + H2O This will form a salt and water. (C)
2) B; strengths of acids are based on their ability to ionize into aqueous solutions. If they completely ionize, they are strong acids, if they partially ionize, they are weak acids.
3) amphoteric is the same as a chemical acting like a base AND or a acid. FeO + H20 ---> H20 and salt
Since there are hydrogens in the water, they self ionize into hydroxides and Fe reacts to form salt. Your only choices would be B and C because they contain oxides which can form a base or acid. It can't be sodium because although it is an alkaline metal, NaO + H20 ----> water and salt, this can only act as a dissociated acid anyhydride. Lead when dissociated, PbO + H20 -----salt + water, this will give you prop. of a base and acid because of the charge on Pb. :) Pb will most likely donate a pair of electrons.
1. c
2.b
3. b
1. c - salt depends on acid used, water result of ionic reaction.
2. b - e.g. ethanoic acid, strength depends on the stability of the anion.
3. b - lead (II) oxide can act as acid and base.
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