stoichiometric quantity वाक्य

However, toxic phosgene is used, and stoichiometric quantities of base ( e . g . pyridine ) are required to neutralize the hydrogen chloride that is cogenerated.
In the first step, a stoichiometric quantity of triethyl aluminium in olefin diluent is reacted with excess ethylene at high pressure ( above 1000 psig ) and relatively low temperature ( below 400 �F ).
A modification has also been reported in which DEAD can be used in catalytic versus stoichiometric quantities, however this procedure requires the use of stoichiometric ( diacetoxyiodo ) benzene to oxidise the hydrazine by-product back to DEAD.
Examples include the Cannizzaro reaction, where approximately 50 % of the reactant aldehyde becomes the other oxidation state of the target, the Wittig reaction, where high-mass phosphorus reagents are used but ultimately become waste, and the Gabriel synthesis, which produces a stoichiometric quantity of phthalic acid
The main disadvantage of direct acylation is the unfavorable chemical equilibrium that must be remedied ( e . g . by a large excess of one of the reagents ), or by the removal of water ( e . g . by using Dean-Stark distillation, anhydrous salts, molecular sieves, or by using a stoichiometric quantity of acid catalyst ).