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Molar mass KOH = <span>56.1056 g/mol
1) Number of moles :
n = m / mm
n = 25.4 / </span><span>56.1056
n =0.452 moles
Volume in liters :
985 mL / 1000 => 0.985 L
Therefore:
M = n / V
M = </span>0.452 / 0.985
=> 0.458 M
Answer:
pH = 11.37
Explanation:
Sodium cyanide will dissociate into sodium ion and cyanide ion. This cyanide ion will get hydrolyzed.The ICE table for hydrolysis of cyanide ion is:
Initial 0.265 0 0
Change -x +x +x
Equilibrium 0.265-x x x
This K is Kb of HCN
Kb = Kw / Ka
Putting values
x can be ignored in denominator as Kb is very low
x= 2.33X10⁻³ M = [OH⁻]
pOH = -log[OH⁻]
pOH = -log(2.33X10⁻³ )
pOH = 2.63
pH = 14- pOH = 14-2.63 = 11.37
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