1) Chemical reaction: HCN + H₂O → CN⁻ + H₃O⁺.
c(HCN) = 2,2 M = 2,2 mol/L.
pKa(HCN) = 9,21.
Ka = 6,16·10⁻¹⁰.
[CN⁻] = [H₃O⁺] = x.
[HCN<span>] = 2,2 M - x.
</span>Ka = [CN⁻] · [H₃O⁺] / [HCN].
6,16·10⁻¹⁰ = x² / 2,2 M -x.
Solve quadratic equation: [CN⁻] = [H₃O⁺] = 0,0000346 M.
[HCN] = 2,2 M - 0,0000346 M = 2,199 M.
2) pH = - log[H₃O⁺].
pH = -log( 0,0000346 M).
pH = 4,46.
Hydrocyanic acid and hydronium ion (H₃O⁺) are acids. Cyanide anion (CN⁻) is the strongest base in the system, cyanide anion accept protons in chemical reaction.
pKb = pKw - pKa.
pKb = 14 - 9,21 = 4,79.
Explanation:
Mole ratio of Ethane to Oxygen = 2 : 7
Moles of O2 needed = 24 moles * (7/2) = 84 moles.
Answer:
0.643 mol.
Explanation:
- We can use the general law of ideal gas: <em>PV = nRT.</em>
where, P is the pressure of the gas in atm (P = 4.0 atm).
V is the volume of the gas in L (V = 4000 mL = 4.0 L).
n is the no. of moles of the gas in mol (n = ??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (T = 30ºC + 273 = 303 K).
<em>∴ n = PV/RT </em>= (4.0 atm)(4.0 L)/(0.0821 L.atm/mol.K)(303 K) = <em>0.643 mol.</em>
The answer is 600. A sample of C3H8O which contains two
hundred molecules, it also holds six hundred carbon atoms. A carbon atom holds
six electrons, four of its electrons are found in its valence shell or also
known as its outer shell.
