The number of potassium atom that are in 0.25 moles potassium carbonate is calculated as follows
by use of Avogadro contant
1 mole= 6.02 x10^23 atoms
what about 0.25 moles,
by close multiplication
{0.250 moles x 6.02 x10^23} / 1 mole = 1.505 x10^23 atoms
Answer:
it may be electron, atom or ions depend on the nature of the substance and the character of reaction
like :- particles per mole, coulombs per electron
Answer is: A) The solution turns blue litmus to red.
Sulfuric acid (H₂SO₄) is a strong acid, it means that the solution of sufuric acid is more acidic (pH<7) than water (pH = 7).
Chemical dissociation of sulfuric acid in water:
H₂SO₄(aq) → 2H⁺(aq) + SO₄²⁻(aq).
When solution turns phenolphthalein pink, it means it is basic (pH>7).
Sulfuric acid has more hydrogen ions (H⁺) and less hydroxide ions (OH⁻) than water.
Answer: 406 hours
Explanation:

where Q= quantity of electricity in coloumbs
I = current in amperes = 39.5 A
t= time in seconds = ?
The deposition of copper at cathode is represented by:

Coloumb of electricity deposits 1 mole of copper
i.e. 63.5 g of copper is deposited by = 193000 Coloumb
Thus 19.0 kg or 19000 g of copper is deposited by =
Coloumb

(1hour=3600s)
Thus it will take 406 hours to plate 19.0 kg of copper onto the cathode if the current passed through the cell is held constant at 39.5 A
Just 2 valence electrons.
Hydrogen already has one to start with, as well. With the exception of hydrogen and helium, all other atoms need 8 valence e-