Answer is: pH of <span>solution of potassium cyanide is 11.2.
</span>Chemical reaction 1: KCN(aq) → CN⁻(aq) + K⁺(aq).
Chemical reaction 2: CN⁻ + H₂O(l) ⇄ HCN(aq) + OH⁻(aq).
c(KCN) = c(CN⁻) = 0.19 M.
pKa(HCN) = 9.21.
Ka(HCN) = 10∧(-9.21) = 6.16·10⁻¹°.
Kb(CN⁻) = 10⁻¹⁴ ÷ 6.16·10⁻¹° = 1.62·10⁻⁵.
Kb = [HCN] · [OH⁻] / [CN⁻<span>].
</span>[HCN] · [OH⁻] = x.
[CN⁻] = 0.19 M - x..
1.62·10⁻⁵ = x² / (0.19 M - x).
Solve quadratic equation: x = [OH⁻] = 0.00174 M.
pOH = -log(0.00174 M) = 2.76.
pH = 14 - 2.76 = 11.2.
Answer:Hydrogen gas is prepared in laboratory by the action of dilute HCl upon granulated zinc. Note: This is a redox reaction since Zn is oxidized and H+ ions is reduced here. Procedure: ... Some crystals of copper sulphate are added to increase the rate of reaction.
Explanation:
The number of moles of 210 grams of NaHCO₃ is 2.5 moles.
<h3>How to find the Number of moles ? </h3>
To calculate the number of moles use the formula
Number of moles =
Mass of NaHCO₃ = 210 g
Now we have to find the Molar mass of NaHCO₃
= Atomic mass of Na + Atomic mass of H + Atomic mass of C + 3 (Atomic mass of O)
= 23 + 1 + 12 + 3 (16)
= 36 + 48
= 84 g/mol
Now put the value in above formula we get
Number of moles =
=
= 2.5 moles
Thus from the above conclusion we can say that The number of moles of 210 grams of NaHCO₃ is 2.5 moles.
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Answer:
The answer to your question is P2 = 84.16 kPa
Explanation:
Data
Volume 1 = V1 = 4.52 L Volume 2 = V2 = 4.83 l
Pressure 1 = P1 = 102 kPa Pressure 2 = P2 = ?
Temperature 1 = T1 = 23°C Temperature 2 = T2 = -12°C
Process
1.- Convert the temperature to °K
Temperature 1 = 23 + 273 = 296°K
Temperature 2 = -12 + 273 = 261°K
2.- Use the Combined Gas law to solve this problem
P1V1/T1 = P2V2/T2
-Solve for P2
P2 = P1V1T2 / T1V2
-Substitution
P2 = (102)(4.52)(261) / (296)(4.83)
-Simplification
P2 = 120331.44 / 1429.68
-Result
P2 = 84.16 kPa
Answer:
D
Explanation:
D. A force acting in the direction opposite the object’s motion is removed from the object