Atitration is performed where 0.150m sodium hydroxide solution is added to a solution of khp.
if 25.00ml was required to reach the end point, how many moles of khp must have been present?

0.00375 moles OF KHP

Explanation:

Equation of reaction of NaOH and KHP :

KHC₈H₄ O₄(aq) + NaOH(aq) → NaKC₈H₄O₄(aq) + H₂O(l)

the reaction required 25ml

Molarity = no of mole / volume in liters

no of moles = Molarity × volume in liters

no of moles of NaOH = 0.150 × (25/1000) = 0.00375 moles

using the balanced equation above

1 mole of NaOH requires 1 mole of KHP

therefore

0.00375 mole of NaOH will require 0.00375 mole KHP.

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol