What reagent would you react with an alkyne to partially reduce it into cis-alkene?
Lindlar's catalyst and H2 are the common reagents used, since the product with this reagents will be a cis- alkene.
Whydoes potassium permanganate can be used in a redox titration as an internal indicator
Potassium permanganate changes color depending whether it is in its reduced or oxidized form. During redox titration, the Mn with a 7+ oxidation state (appeared as purple) will be reduced into 2+ oxidation state (appeared as colourless)
What could be the main reasons why actual yield is always less than theoretical yield?
Some reactions are reversible and do not proceed 100% to the product side. The difficulty of obtaining products from the aqueous medium or other medium can also lowers the yield. Lastly, most reaction are complex and their reaction among other reactant or among themselves can be uncontrollable and would result in lower amount of your expected product.