Answer:
Ka = 1.39x10⁻⁶
Explanation:
A monoprotic acid, HX, will be in equilibrium in an aqueous medium such as:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
<em>Where Ka is:</em>
Ka = [H⁺] [X⁻] / [HX]
<em>Where [] is the molar concentration in equilibrium of each specie.
</em>
The equilibrium is reached when some HX reacts producing H+ and X-, that is:
[HX] = 1.64M - X
[H⁺] = X
[X⁻] = X
As pH is 2.82 = -log [H⁺]:
[H⁺] = 1.51x10⁻³M:
[HX] = 1.64M - 1.51x10⁻³M = 1.638M
[H⁺] = 1.51x10⁻³M
[X⁻] = 1.51x10⁻³M
And Ka is:
Ka = [1.51x10⁻³M] [1.51x10⁻³M] / [1.638M]
<h3>Ka = 1.39x10⁻⁶</h3>
<span>
Sodium Oxide= Na2O
The formula mass of Na2O is (2x23) + 16 = 62g/mol
% Na= (46/62) x 100 = 74%
% O= (16/62) x 100 = 26%</span><span>
</span>
Answer:
No
Explanation:
Atomic number represents the identity of atoms
using number of protons which is equal in isotopes.
Answer:The mole is important because it allows chemists to work with the subatomic world with macro world units and amounts. Atoms, molecules and formula units are very small and very difficult to work with usually. However, the mole allows a chemist to work with amounts large enough to use.
Explanation:
Answer:
A.The concentration of water is greater outside the cell than inside the cell.
Explanation:
The contractile vacuole of certain organisms functions to regulate water flow in and out of the cell. It does this by storing excess water that comes into the cell. In the case of this organism with a filled up contractile vacuole, it means water is flowing into the cell.
Naturally, water will flow into a living cell when an osmotic gradient i.e. difference in concemtration, has been created between intracellular and extracellular solutions. Osmosis involves movement of substances from a region of high water concentration to a region of low water concentration. This means that if water is flowing into the cell, which is stored by the contractile vacuole, the concentration of water must be greater outside the cell than inside.
