Answer:
29.41% of Calcium and 47.04% of Oxygen
Explanation:
The percent composition of an atom in a molecule is defined as 100 times the ratio between the mass of the atom and the mass of the molecule.
The mass of the molecule of the problem (Ore) is 46.28g. That means the percent composition of Calcium is:
13.61g / 46.28g * 100 = 29.41% of Calcium
And percent composition of Oxygen is:
21.77g / 46.28g * 100 = 47.04% of Oxygen
The formation of nitric acid from nitrogen, hydrogen, and oxygen can be written as,
N₂ + H₂ + 3O₂ --> 2HNO₃
The net enthalpy of formation of nitric acid is calculated by,
Hrxn = Hproduct - Hreactant
Since all the reactants are in their elemental forms, the simplified equation would be,
Hrxn = Hproduct
Substituting,
Hrxn = (-186.81 kJ/mol)(2 mols)
<em>Answer: -372.42 kJ</em>
So you need to find the volume in L? If so:
Convert the mass of Lithium Bromide into moles by dividing the 100 grams by the molar mass of LiBr, taken from the periodic table
In a solution, moles = (concentration in mole/L) x (volume in L)
We know the moles, we have the concentration in mole/L, now find the volume in L, and you should get 0.288. Plz do the math and check for yourself
