B)hydrogen ...................
Answer:
1.35 moles of O²⁻
21.6 grams of O²⁻
Explanation:
We know that the charge on Aluminium ion is +3 (i.e. Al³⁺) while, the charge on Oxide ion is -2 (i.e. O²⁻). Therefore, the overall neutral Al₂O₃ compound has 2 Al³⁺ ions and 3 O²⁻ ions. Since, we can say that,
1 mole of Al₂O3 contains = 3 moles of O²⁻ ions
So,
0.450 moles of Al₂O₃ will have = X g of O²⁻
Solving for X,
X = 0.450 mol × 3 mol ÷ 1 mol
X = 1.35 moles of O²⁻
As the mass of an atom is mainly due to the presence of protons and neutrons hence, the addition of two electrons (-ve 2 shows two gained electron) to Oxygen will make a negligible change to the atomic masss of Oxygen because electron is said to be almost 1800 times lighter than proton. Hence, the ionic mass of O²⁻ will be 16 g/mol and the mass of given moles is calculated as,
Mass = Moles × Ionic Mass
Mass = 1.35 mol × 16 g/mol
Mass = 21.6 g
White when dry , dry grainy. When get hello and Paste
Answer:
607 ppm
Explanation:
In this case we can start with the <u>ppm formula</u>:
If we have a solution of <u>0.0320 M</u>, we can say that in 1 L we have 0.032 mol of 
, because the molarity formula is:
In other words:
If we use the <u>atomic mass</u> of 
(19 g/mol) we can convert from mol to g:
Now we can <u>convert from g to mg</u> (1 g= 1000 mg), so:
Finally we can <u>divide by 1 L</u> to find the ppm:
<u>We will have a concentration of 607 ppm.</u>
I hope it helps!
