At the end of a reaction it is important to remove the solvent from a solid product (more than one answer may be correct): a. So that the melting point can be determined.
b. So that clean NMR spectra can be obtained that do not contain solvent peaks.
c. So that the yield can be determined.
d. So that the solvent can be reused.

(B.) and (C.)

b. So that clean NMR spectra can be obtained that do not contain solvent peaks.

c. So that the yield can be determined.

Explanation:

The solvent used in Nuclear Magnetic Resonance (NMR) spectrometer is Trimethyl silane (TMS), a neutral solvent which doesn't give off any signals. Other solvents could have interactions with the radiation, and disrupt the spectra.

Furthermore, for accurate determination of the actual yield and overall percentage yield, solid must be separated from the solvent, dried and weighed.

I hope this was explanatory enough.

the answer is 75.0%.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.