What is the annount of hydrochloric acid present in its aqueous solution having PH=2 in gL-1? (molar mass of hydrochloric acid=36.5g mol-1)
(1) 3.65
(2) 7.30
(3) 0.365
(4) 0.730
Answers
pH of Hydrochloric Acid
Acidity and Alkalinity (pH)
An acid is a substance that yields hydrogen ions (H+
)
when dissolved in water, while bases are substances
that yield hydroxide ions (OH-
). Strong acids or bases
ionize nearly completely in water to yield many
hydrogen ions or hydroxide ions.
Pure water ionizes slightly to produce an equivalent
number of [H+
] and [OH-
] ions. Any solution
containing equal concentrations of [H+
] and [OH-
] is
neutral. Any solution with an excess of [H+
] is acidic.
Any solution with an excess of [OH-
] is basic.
pH
The relative strength of an acid or base is found by
comparing the concentration of [H+
] in solution with
that of water. The hydrogen-ion concentration [H+
]
expressed as a power of 10 is known as the pH. By
definition pH is equal to the negative logarithm of the
hydrogen-ion concentration.
pH = -log[H+
] = log 1/[H+
]