Question

What is the \[pH\] of \[N{a_2}C{O_3}\], sodium carbonate?

Answer 1

Hint: \[pH\] denoting 'potential of hydrogen' or 'power of hydrogen' is a scale used to specify the acidity or basicity of an aqueous solution. Acidic solutions (solutions with higher concentrations of \[{H^ + }\] ions) are measured to have lower \[pH\] values than basic or alkaline solutions. At \[25^\circ C\], solutions with a \[pH\] less than \[7\] are acidic, and solutions with a \[pH\] greater than \[7\] are basic.

Complete answer:
The \[pH\] of sodium carbonate in water is close to \[11\]. The \[pH\] is influenced by several factors in which concentration is an important one. Therefore, the \[pH\] of sodium carbonate changes with the level of concentration of it in water. At \[25^\circ C\], the change in \[pH\] for different concentrations can be observed as follows:
-The \[pH\] of \[1wt\% \] sodium carbonate solution is \[11.37\].
-The \[pH\] of \[5wt\% \] sodium carbonate solution is \[11.58\].
-The \[pH\] of \[10wt\% \] sodium carbonate solution is \[11.70\].
Instead of using the weight percentage we can use the mass of sodium carbonate added in water. Thus, for \[1wt\% \], we can write \[1g\] of sodium carbonate in water and so on.
Hence, we can say that the value of \[pH\] keeps increasing with increased concentration of the solution.

Note:
The sodium carbonate solution is an aqueous solution and aqueous solutions are strongly alkaline. The \[pH\] scale is logarithmic and inversely indicates the concentration of hydrogen ions in the solution. This is because the formula used to calculate \[pH\] approximates the negative of the base \[10\] logarithm of the molar concentration of hydrogen ions in the solution. More precisely, \[pH\] is the negative of the base 10 logarithm of the activity of the \[{H^ + }\] ion.