In standardizing the solution of aqueous sodium hydroxide, a chemist overshoots the end point and adds too much naoh(aq). would this error result in a calculated concentration of naoh that was overestimated or underestimated? explain your reasoning.

Concentration of NaOH calculated will be underestimated.

Explanation:

End point is an observational point , which tells us about the completion of reaction between the titrant (solution in burette) and titre(solution in conical flask) in titration experiment.

In this case , NaOH is titrant whose concentration is unknown.

,

,

....(1)

According to question a chemist overshoots the end point and adds to much of NaOH solution, which means increase in the value of .

Then the value of in equation (1), will get lowered , which means that the concentration of NaOH was lower than that of the actual value. Hence underestimated concentration of NaOH.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"