Chemistry
Define pH value. What would you say about the pH of a solution in which
(i) H+ aq. ions = OH- ions
(ii) evolves CO2 when heated with Na2CO3
(iii) OH-ions > H+ aq. ions.
Answer
pH is defined as the negative logarithm [to the base 10] of the hydrogen ion concentration expressed in moles/litre. Thus, pH = -log10H+. It represents the strength of acids and alkalis, expressed in terms of hydrogen ion concentration [H+ aq.]
(i) When, H+ ions = OH- ions, the solution is neutral with pH = 7.
(ii) When the solution evolves CO2 when heated with Na2CO3, it is acidic in nature with pH less than 7.
(iii) when, OH-ions > H+ aq. ions, the solution is basic in nature with pH more than 7.
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