An acid$-$base buffer is a solution that resists changes in $pH$ when a small amount of strong acid or base is added. Acid$-$base buffers typically contain a weak acid and its conjugate base.

$1$st attempt

Part $1(1$ point$)$

See Periodic Table

See Hint

Calculate the $pH$ of a buffer containing $0\mathrm{.}155MHN{O}_2$ and $0\mathrm{.}170MNaN{O}_2$ at $25C.$ The $p{K}_a$ value for $HN{O}_2$ is $3\mathrm{.}40.$

Part $2(1$ point$)$

See Hint

Calculate the $pH$ of the buffer after the addition of $1\mathrm{.}087mL$ of $11\mathrm{.}552MHCl$ to $1\mathrm{.}00L$ of the buffer.