What are the configuration of the two chiral centre?

Find the sum of all the stereocenters that are present in below compounds

An organic compound $^1C{H_3}{ - ^2}C{H_2}{ - ^3}C{H_2}{ - ^4}C{H_2}{ - ^5}C{H_2}{ - ^6}C{H_2}{ - ^7}C{H_3}$

To make it chiral compound the attack should be on which carbon atom

It is possible to distinguish between optical isomers by

The number of meso form of the given compound is

$\begin{array}{*{20}{c}}
  {C{H_3} - CH - CH - CH - C{H_3}} \\ 
  {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,} \\ 
  {OH\,\,\,\,\,\,\,OH\,\,\,\,\,OH\,\,} 
\end{array}$

An enantiomerically pure acid is treated with racemic mixture of an alcohol having one chiral carbon. The ester formed will be