a.
\(\mathrm{pH} = -\lg[\mathrm{H^+}] = -\lg 0,001 = 3,0\)
b.
\(\mathrm{pH} = -\lg[\mathrm{H^+}] = -\lg 0,0000021 = 5,67778071 ≈ 5,68\)
c.
\(\mathrm{pH} = -\lg [\mathrm{H^+}] = -\lg(8,7 \cdot 10^{-9}) = 8,06048075 ≈ 8,06\)
d.
\(\mathrm{pH} = -\lg [\mathrm{H^+}] = -\lg 2,5 = -0,39794001 ≈ -0,40\)
