Answer:
The (H30+) is 4,13x10-8
Explanation:
We use the formula
Kwater = (H30 +) x (OH-)
1.00e-14 = (H30 +) x 2.42e-7
(H30 +) = 1.00e-14 / 2.42e-7 = 4.13e-8M
Answer;
68.46 g of sucrose in 100mL
Solution and explanation;
Given 2L of 2 mol/L sucrose solution
Moles = concentration x volume
Therefore; The number of moles in this solution is 2 L x 2 mol/L = 4 mol
The molecular mass of sucrose is 342.3 g/mol.
Mass = Moles × Molecular weight
Therefore the mass of sucrose in 2 L;
= 4 mol x 342.3 g/mol = 1369.2g
but; 2L/20 = 100 mL
= 1369.2/20 = 68.46
Hence; you would have 68.46 g in 100 mL
Answer:
Na₂SO₄
Explanation:
Barium nitrate, Ba(NO₃)₂ produce precipitate with SO₄²⁻, CO₃²⁻. That means the precipitate could be obtained from Na₂SO₄ and Na₂CO₃.
Also, magnesium nitrate, Mg(NO₃)₂, produce precipitate just with CO₃²⁻. As the unknown solution produce no precipitate, the unknown compound is:
<em>Na₂SO₄</em>
Arsenic's atomic number is 33.
Hence his electronic configuration is

hence his valence electrons are

.
5 valence electrons
I really don't know what the answer is