Answer:
pKa of the acid HA with given equilibrium concentrations is 6.8
Explanation:
The dissolution reaction is:
HA ⇔ H⁺ + A⁻
So at equilibrium, Ka is calculated as below
Ka = [H⁺] x [A⁻] / [HA] = 2.00 x 10⁻⁴ x 2.00 x 10⁻⁴ / 0.260
= 15.38 x 10⁻⁸
Hence, by definition,
pKa = -log(Ka) = - log(15.38 x 10⁻⁸) = 6.813
One mole of copper equals 6.02 × 10^23 atoms. The answer is letter C. This follows the
Avogaro’s law wherein 1 mole of a substance is equal to 6.02 x 10^23 atoms,
formula units or molecules. This is applicable to all substances.
Riley can either change the surface area of the object or can change the slipperiness of the material.
Answer:
Around 450 B.C.
Explanation:
The idea was forgotten until the 1800 when John Dalton re-introduced the atom.
