Moles are used conveniently in chemistry especially in stoichiometric calculations involving reactions. The unit of mole is a collective term that holds 6.022×10^23 particles. These particles is a general term for any small units of matter including molecules, atoms and sub-particles. This ratio of 6.022×10^23 particles to 1 mole is known to be the Avogadro's number. Its exact number is actually <span>6.0221409</span>×10^23. We use this constant in our stoichiometric calculation as follows:
15 moles oxygen * (6.022×10^23 molecules/ 1 mole oxygen) = 9.033×10^24 molecules of oxygen
I think it’s 20 mol
Sorry if I’m wrong
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
Answer:
Activation energy is needed so reactants can move together, overcome forces of repulsion, and to begin breaking bonds.
Explanation:
Answer:
a) Ka= 7.1 × 10⁻⁴; This is a weak acid because the acid is not completely dissociated in solution.
Explanation:
Step 1: Write the dissociation reaction for nitrous acid
HNO₂(aq) ⇄ H⁺(aq) and NO₂⁻(aq)
Step 2: Calculate the acid dissociation constant
Ka = [H⁺] × [NO₂⁻] / [HNO₂]
Ka = 0.022 × 0.022 / 0.68
Ka = 7.1 × 10⁻⁴
Step 3: Determine the strength of the acid
Since Ka is very small, nitrous acid is a weak acid, not completely dissociated in solution.
