Respuesta :
Answer: 3.48 kJ of heat is released when 155.0 mL of 0.400 M HCl is mixed with 157.0 mL of 0.500 M NaOH
Explanation:
To calculate the number of moles for given molarity, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in L)}}[/tex] .....(1)
Molarity of [tex]HCl[/tex] solution = 0.400 M
Volume of solution = 155.5 mL
Putting values in equation 1, we get:
a) [tex]0.400M=\frac{\text{Moles of}HCl\times 1000}{155.5ml}\\\\\text{Moles of }HCl=\frac{0.400mol/L\times 155.5}{1000}=0.0622mol[/tex]
b) [tex]0.500M=\frac{\text{Moles of}NaOH\times 1000}{157.0ml}\\\\\text{Moles of }NaOH=\frac{0.500mol/L\times 157.0}{1000}=0.0785mol[/tex]
[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]
According to stoichiometry;
1 mole of [tex]HCl[/tex] reacts with 1 mole of [tex]NaOH[/tex]
Thus 0.0622 moles of [tex]HCl[/tex] reacts with= [tex]\frac{1}{1}\times 0.0622=0.0622[/tex] moles of [tex]NaOH[/tex]
Thus HCl is the limitibg reagent and NaOH is in excess
1 mole of HCl gives = 56 kJ
Thus 0.0622 moles of HCl gives =[tex]\frac{56}{1}\times 0.0622=3.48kJ[/tex]
Thus 3.48 kJ of heat is released when 155.0 mL of 0.400 M HCl is mixed with 157.0 mL of 0.500 M NaOH
