Question

30ml of a 1.25M aqueous silver nitrate solution is mixed with 20 ml of a .1M aqueous magnesium chloride solution. in the process, silver chloride precipitates from the resulting solution 246 joules of heat are liberated. What is the enthalpy change of precipitation for silver chloride

Answer 1

Equation is

2AgNO₃ + MgCl₂ 2 AgCl + MgNO₃ Q= 246 joules

Silver nitratre concentration is 1.25 M , volume is 30 moles

= enthalpy change of precipitation of silver chloride

Q = 246 joules

first, we have to find out the number moles

According to balanced equation moles of AgNO3 = moles of AgCl

n(AgNO_3(aq)) = n(AgCl_(s))

n(AgNO_3(aq)) = molarity × volume
n = moles((AgNO3)_aq)) /
n =molesX V in ml/1000/

n = 1.25 X30/1000/= 0.0375 M

= 246/0.0375 = 3280 joules/Moles

= 6.56 KJ/ Moles