For the following errors, determine if the error will affect the calculation of
ID: 878687 • Letter: F
Question
For the following errors, determine if the error will affect the calculation of qsystem. If it does affect the calculation, then state if it will increase or decrease the value of qsystem.
a. Placing the hot aluminum rod on the lab bench for 30 seconds before adding it to the calorimeter.
b. Adding 50 mL of water, but only recording the volume of water as 30 mL.
c. The solid NH4NO3 did not all dissolve after adding it to the water.
d. Some of the HCl splashed out while pouring it into the calorimeter.
Explanation / Answer
a. Placing the hot aluminum rod on the lab bench for 30 seconds before adding it to the calorimeter it release some energy to surrounding hence it will decrease the value of qststem.
b. Adding 50 mL of water, but only recording the volume of water as 30 mL
qH2O=qM
mH2OcspH2O(l)(T)=Mm*MspCuT
If recorded less amount of water then all calculation will be affected and the amount of qH2O= mH2OcspH2O(l)(T); means the value of qsystem will also decrease.
c. The solid NH4NO3 did not all dissolve after adding it to the water.
The calorimeter is used for calculation the Enthalpy of Reaction for the Dissolution of Salts like NH4NO3 by the following reaction but the solid NH4NO3 did not all dissolve after adding it to the water then the value of qsoln will be decrease, which affect the total heat transfer and the value of qsystem will also decrease.
qRxn=–(qsoln+ qcal)
d. Some of the HCl splashed out while pouring it into the calorimeter, means the amount of HCl is reduced before pouring it into the calorimeter then all calculation will be affected and the amount of qHCl= mHClcspHCl(l)(T); means the value of qsystem will also decrease