Question

К раствору фенола прилили бромную воду до прекращения выпадения осадка, а на нейтрализацию фильтрата израсходовано 100 мл 0,3М раствора гидроксида калия. Количество вещества фенола

Answer 1

C6H5OH + 3Br2 = C6H2Br3OH + HBr
C6H2Br3OH + KOH = C6H2Br3OK + H2O
По формуле Cm=n/V найдем количество KOH
100 мл=0,1 л
n(KOH)=0,3х0,1=0,03 моль
n(C6H5OH)=n(KOH)=0,03 моль 

Answer 2

Calculating the Amount of Phenol

To calculate the amount of substance of phenol, we can use the information provided about the reaction and the volume and concentration of the potassium hydroxide solution used for neutralization.

Given: - Volume of potassium hydroxide solution (V) = 100 mL - Concentration of potassium hydroxide solution (C) = 0.3 M

The balanced chemical equation for the reaction between phenol and bromine water is not provided. However, we can use the information about the neutralization reaction with potassium hydroxide to calculate the amount of phenol.

The reaction between phenol and bromine water is likely to form 2,4,6-tribromophenol as the precipitate. The balanced chemical equation for the neutralization reaction between phenol and potassium hydroxide is:

C6H5OH + KOH → C6H5OK + H2O

From the balanced equation, we can see that 1 mole of phenol reacts with 1 mole of potassium hydroxide.

Calculation

The amount of substance of potassium hydroxide (n) can be calculated using the formula:

n = C * V

Where: - C = concentration of the solution in moles per liter (M) - V = volume of the solution in liters (L)

Substituting the given values: n = 0.3 mol/L * 0.1 L = 0.03 moles of KOH

Since 1 mole of phenol reacts with 1 mole of potassium hydroxide, the amount of substance of phenol is also 0.03 moles.

Therefore, the amount of substance of phenol is 0.03 moles.