$pH$ of $HCl$ $(10^{-12} \ M)$ is

What is the $pH$ of a $2.6 \times 10^{-8} \ M \ H^{+}$ ion solution?
$(\log 2.6 = 0.4150)$

An aqueous solution of $HCl$ with $pH \ 1.0$ is diluted by adding an equal volume of water (ignoring the dissociation of water). The $pH$ of the $HCl$ solution would be (Given $\log 2 = 0.30$):

Calculate the $pH$ of $0.0035 \ M \ Ba(OH)_2$ solution.

What is the $pH$ of a $10^{-8} \ M$ solution of $HCl$?

Calculate the $pH$ of the following solutions:
$(a)$ $2 \,g$ of $TlOH$ dissolved in water to give $2 \,L$ of solution.
$(b)$ $0.3 \,g$ of $Ca(OH)_2$ dissolved in water to give $500 \,mL$ of solution.
$(c)$ $0.3 \,g$ of $NaOH$ dissolved in water to give $200 \,mL$ of solution.
$(d)$ $1 \,mL$ of $13.6 \,M \,HCl$ is diluted with water to give $1 \,L$ of solution.