( ( yields ( from ( equilibrium reactions ) ) ) ( ( ( can sometimes ) ( be ( improved ( by ( changing ( ( the conditions ) ( ( ( the products ) ( from ( competing reactions ) ) ) ( ( ( ( may or ) may ) not ) ( ( ( be ( useful ( competing reactions ) ) ) , ) ( giving ( ( other products ) ( which ( might ( be ( ( ( difficult or ) expensive ) ( to ( separate ( from ( the ( main product ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS yields)) (PP (IN from) (NP (NN equilibrium) (NNS reactions)))) (VP (MD can) (ADVP (RB sometimes)) (VP (VB be) (VP (VBN improved) (PP (IN by) (S (VP (VBG changing) (NP (NP (DT the) (NNS conditions)) (SBAR (S (NP (NP (DT the) (NNS products)) (PP (IN from) (NP (VBG competing) (NNS reactions)))) (VP (MD may) (CC or) (MD may) (RB not) (VP (VB be) (NP (JJ useful) (VBG competing) (NNS reactions)) (, ,) (S (VP (VBG giving) (NP (NP (JJ other) (NNS products)) (SBAR (WHNP (WDT which)) (S (VP (MD might) (VP (VB be) (ADJP (JJ difficult) (CC or) (JJ expensive) (S (VP (TO to) (VP (VB separate) (PP (IN from) (NP (DT the) (JJ main) (NN product))))))))))))))))))))))))) (. .)))
yields from equilibrium reactions can sometimes be improved by changing the conditions the products from competing reactions may or may not be useful competing reactions, giving other products which might be difficult or expensive to separate from the main product.
(ROOT (S (NP (NP (DT The) (NN amount)) (PP (IN of) (NP (NP (NN product)) (SBAR (WHNP (WDT that)) (S (VP (MD may) (VP (VB be) (VP (VBN produced) (PP (IN by) (NP (DT a) (NN reaction))) (PP (IN under) (NP (VBN specified) (NNS conditions))))))))))) (VP (VBZ is) (VP (VBN called) (NP (JJ theoretical) (NN yield)))) (. .)))
The amount of product that may be produced by a reaction under specified conditions is called theoretical yield.