Brønsted–Lowry model:

• Acids are proton donors

• e.g. HCl can ionise and produce hydrogen ions in aqueous solution

• Thus HCl is an acid.

  • $HCl_{(aq)} \rightarrow H^{+}{(aq)}+Cl^-{(aq)}$
  • Better equation: $HCl_{(aq)} + H_{2}O_{(l)} \rightarrow H_3O^{+}{(aq)}+Cl^-{(aq)}$

• Monoprotic acids: Acids that produce one proton for every 1 molecule of acid that ionises.

• Sulfuric acid is an example of diprotic acids: $H_{2}SO_{4} \rightarrow H^{+}+HSO_4^-$

  • $HSO_{4}^{-}\rightarrow H^{+} + SO_4^{-2}$

• Nitric acid: $HNO_{3(aq)}$

• These are examples of strong acids.

• Strong acids: ionise completely.

  • We use arrows going in one direction, because all of these molecules in water will ionise
  • There is a difference between strength of acids and concentration of acids.

• Weak acids: acids that do not ionise completely (ionise partially).

  • e.g. $CH_3COOH$, $HNO_2$, $H_2SO_3$, $H_3PO_4$, $H_2C_2O_4$
  • ⇌ - use this symbol when describing reactions with weak acids.

• $H_2C_2O_{4(aq)}⇌H^{+}_{(aq)}+HC_2O{4(aq)}^{-}$

• $HC_2O_{4(aq)}^{-}⇌H^{+}{(aq)}+C_2O{4(aq)}^{2-}$

Def answer for Brønsted–Lowry strong acid

• (1) proton donor

• (1) ionises completely

• (3) equations

• (1) mono/diprotic?

• Base: a proton acceptor

  • e.g. $OH^{-}{(aq)}+H^{+}{(aq)}\rightarrow H_2O_{(l)}$

• Strong base: ionise completely.

  • Group 1 hydroxides.
  • $Ca(OH)_2$
  • $Ba(OH)_2$

• $Ca(OH){2(aq)}\rightarrow Ca^{2+}{(aq)}+2OH^{-}_{(aq)}$ - note this also goes in stages like polyprotic acids

• Weak base: ionise or dissociate partially.

  • $NH_4OH_{(aq)}⇌NH_4^{+}+OH^-_{(aq)}$
  • $NH_{3}+ H_{2}O⇌NH_4^{+}+OH^-$ - extension

Recall

Summary

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