Answer:
D
Explanation:
I took a study island on this
Answer:
.122 mols of KCl
Explanation:
<u>Read the explanation </u><u><em>while</em></u><u> looking at the picture.</u>
We star with 15g because it's wat they give us:
<u>15g of KCIO3 will cancel out with 123g of KCIO3</u> (molar mass)
~Grams of KCIO3 are canceled out.~
<u>That 123g of KCIO3 is the same as 1 mol of KCIO3</u>
Then we use mole to mole ratio:
<u>1 mol of KCIO3 equals 2 mols of KCIO3</u> -- 2 moles from the equation
The <u>2 mols of KCIO3 is equal to 2 mols of KCl</u> (from equation)
Multiply the numbers on top. Multiply the numbers on the bottom. Then divide. You get:
This sounds confusing. But the picture below is the format.
The SAME COLOR are the ones that cancel out.
Answer:
155.4 g of Al₂O₃
Explanation:
The reaction is:
4Al(s) + 3O₂(g) → 2Al₂O₃(s)
To determine the mass of aluminum oxide that is formed we need to know the limiting reagent. Let's calculate the moles of each by the molar mass
Mass / molar mass = Moles
82.49 g / 26.98 g/mol = 3.05 moles of Al
117.65 g / 32 g/mol = 3.67 moles of oxygen
Let's try the oxygen. Ratio is 3:4.
3 moles of O₂ need 4 moles of Al to react
Therefore 3.67 moles of O₂ will react with (3.67 . 4 )/3 = 4.90 moles
We only have 3.05 moles of Al, so the Al is the limiting reactant
Now, we work with stoichiometry
4 moles of Al can produce 2 moles of Al₂O₃
3.05 moles of Al will produce (3.05 .2) / 4 = 1.52 moles of Al₂O₃
We convert the moles to mass: 1.52 mol . 101.96 g / 1mol = 155.4 g
Each molecule of Sr₃(PO₄)₂ contains 3 moles of Sr
So 3 moles of Sr⁺² ions are in one mole of Sr₃(PO₄)₂.