From the following reactions,predict which of the following orders regarding acid strength is correct? $\begin{array}{1 1}HC\equiv CH+LiNH_2\quad\leftrightharpoons\quad NH_3+HC\equiv CLi\\NH_3+R^-\quad\leftrightharpoons \quad NH_2^-+RH\end{array}$

$\begin{array}{1 1}(a)\;RH < NH_3 < HC \equiv CH\\(b)\;RH > NH_3 > HC \equiv CH\\(c)\;RH > NH_3 < HC \equiv CH\\(d)\;RH < NH_3 > HC \equiv CH\end{array}$

$HC\equiv CH+LiNH_2\quad\leftrightharpoons\quad NH_3+HC\equiv CLi$
$\Rightarrow HC\equiv CH > NH_3$
$NH_3+R^-\quad\leftrightharpoons \quad NH_2^-+RH$
$\Rightarrow NH_3 > RH$
Hence (a) $RH < NH_3 < HC \equiv CH$ is the correct option.
answered Mar 21, 2014