Post-Laboratory Questions ee the spcon proeided for the es a additional peper if
ID: 588662 • Letter: P
Question
Post-Laboratory Questions ee the spcon proeided for the es a additional peper if ecessary 1. A stodent was given only one graduated cylinder to use for this experiment. After using it to measure 500 mL of the assigned acid, the student iailed to rinse or dry the cylinder before measuring out the 50.5 mL of the base. Would the calculated &Hom; be higher, lower, or the same as the literature Hon? Brilefly explain this diffenence as a result of using only one graduated cylinder for the xCaucuaied Hneuizn wiube higher than me iesatureH neuzn in tnis cose. tha reason is that sirce cinder used usithout rinsing ontains idte the aase requuroduu be more ban the c Ckua tn caces Hon 2 Explain how the following changes in the procedure for this experiment would affect the results a) A glass beaker was used instead of a pressed polystyrene cup. A pressed polystyrene top was used to cover the polystyrene cup after the acid and base solutions had been mixed. 2) 53Explanation / Answer
Ans 1 :
The enthalpy of neutralization is the enthalpy change when the acid and base react together to form 1 mole of water under the standard conditions. Here since the base has been measured in the graduated cylinder that already had some amounts of acid sticking to it , the amount of measured base in the reaction will be lower than the assumed amount.
There will be more of acid in the reaction , due to which base will become the limiting reagent in the reagent. Due to this reason less number of water molecules will be formed , and certain amount of acid will remain unreacted.
So the enthalpy of neutralisation will decrease.