<span>The Answer </span>should be<span> .074 M</span>
The standard atomic weight is the average mass of an element in atomic mass units ("amu"). Though individual atoms always have an integer number of atomic mass units, the atomic mass on the periodic table is stated as a decimal number because it is an average of the various isotopes of an element.
Answer:
M Na2SO4 sln = 0.8448 M
Explanation:
∴ mass Na2SO4 = 3.00 g
∴ volume soln = 25 mL = 0.025 L
∴ molar mass Na2SO4 = 142.04 g/mol
⇒ mol Na2SO4 = (3.00 g)*(mol/142.04 g) = 0.02112 mol
⇒ M Na2SO4 sln = (0.02112 mol/0.025 L ) = 0.8448 M
Delta H of solution = -Lattice Energy + Hydration
<span>Delta H of solution=- (-730)+(-793) </span>
<span>Delta H of solution= -63kJ/mol </span>
<span>Now we find moles of LiI: </span>
<span>10gLiI/133.85g=.075moles </span>
<span>multiply moles to the delta H of solution to cross cancel moles. .75moles x -64kJ/mol =4.7</span>
