<span>Answer is: pH of solution of sodium cyanide is 11.3.
Chemical reaction 1: NaCN(aq) → CN</span>⁻(aq)
+ Na⁺<span>(aq).
Chemical reaction 2: CN</span>⁻ +
H₂O(l) ⇄ HCN(aq) + OH⁻<span>(aq).
c(NaCN) = c(CN</span>⁻<span>)
= 0.021 M.
Ka(HCN) = 4.9·10</span>⁻¹⁰<span>.
Kb(CN</span>⁻) = 10⁻¹⁴ ÷
4.9·10⁻¹⁰ = 2.04·10⁻⁵<span>.
Kb = [HCN] · [OH</span>⁻]
/ [CN⁻<span>].
[HCN] · [OH</span>⁻<span>] =
x.
[CN</span>⁻<span>] = 0.021 M - x..
2.04·10</span>⁻⁵<span> = x² / (0.021 M
- x).
Solve quadratic equation: x = [OH</span>⁻<span>] = 0.00198 M.
pOH = -log(0.00198 M) = 2.70.
pH = 14 - 2.70 = 11.3.</span>
A mutation that gives a rabbit a third ear
Answer:
i'm sorry i forgot this answer i just had it
Explanation:
<span>Answer:
3 electron pairs
Let's take BF3 for an example.
When you find the valence electrons for this molecule --> [3+(3x6)], you'll get 24e-. You draw the Lewis dot structure and each of the F atom would have six dots around it (a total of 18 because there's 3 F atoms) and the B would have three lines [one line attached to each F. One line would equal to 2 valence electrons] and you get a total of 24 valence e-.
The question asks how many groups are on the CENTRAL atom, meaning on the B. It would be three</span>
