The average atomic mass of Sn is 118.71 g/mol
the percentage of heaviest Sn is 5.80%
the given mass of Sn is 82g
The total moles of Sn will be = mass / atomic mass = 82/118.71=0.691
Total atoms of Sn in 82g =
the percentage of heaviest Sn is 5.80%
So the total atoms of = 5.80% X
Total atoms of =
atoms
the mass of will be =
Answer: The standard enthalpy of formation of is -252.1 kJ/mol.
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
Putting the values we get :
Thus standard enthalpy of formation of is -252.1 kJ/mol.
Answer:
A mixture of 100. mL of 0.1 M HC3H5O3 and 50. mL of NaOH
Explanation:
The pH of a buffer solution is calculated using following relation
Thus the pH of buffer solution will be near to the pKa of the acid used in making the buffer solution.
The pKa value of HC₃H₅O₃ acid is more closer to required pH = 4 than CH₃NH₃⁺ acid.
pKa = -log [Ka]
For HC₃H₅O₃
pKa = 3.1
For CH₃NH₃⁺
pKa = 10.64
pKb = 14-10.64 = 3.36 [Thus the pKb of this acid is also near to required pH value)
A mixture of 100. mL of 0.1 M HC3H5O3 and 50. mL of NaOH
Half of the acid will get neutralized by the given base and thus will result in equal concentration of both the weak acid and the salt making the pH just equal to the pKa value.