$($Fundamentals Sections E and F$)$ Lithium diisopropylamide $($LDA$)$ is a strong base used in organic synthesis. LDA has a molecular formula of $C_6{H}_{14}$LiN and it is a liquid at room temperature $($density $=0\mathrm{.}79\frac{g}{m}L).$

$($a$)$ How many molecules of LDA are present in $6\mathrm{.}1$mmol $?$

$($b$)$ Convert $65$mmol of LDA into grams.

$($c$)$ Calculate the volume of $65$mmol of LDA.

$($d$)$ While pure LDA can spontaneously ignite, LDA in solution is not pyrophoric. Calculate the volume of a $2\mathrm{.}0M$ solution required to get $350$mmol of LDA.