23.8 ml of a 2.0 mol/l surfuric acid solution reacted completely with 68.0 ml of potassium hydroxide. find the concentration of potassium hydroxide
2KOH + H2SO4 ==> K2SO4 + 2H2O
mols H2SO4 = M x L = ?
mols KOH = 1/2 that (from the coefficients in the balanced equation)
Then M KOH = mols KOH/L KOH
there is one mole of H2SO4
AND TWO MOLES OF KOH
0.0476 MOLE H2SO4(2MOLES KOH/ONE MOLE H2SO4)
TWICE THAT OF THE BALANCED EQUATION
0.0952 MOL KOH/0.068 LITERS KOH =1.4 MOLE/LITER KOH
To find the concentration of potassium hydroxide in this reaction, we can use the concept of stoichiometry.
Stoichiometry is a mathematical approach that relates the amount of reactants and products in a chemical reaction. In this case, we know the volume and concentration of sulfuric acid and the volume of potassium hydroxide that reacted. We want to find the concentration of potassium hydroxide.
First, let's write the balanced chemical equation for the reaction:
H2SO4 + 2KOH -> K2SO4 + 2H2O
From the equation, we can see that the ratio between sulfuric acid (H2SO4) and potassium hydroxide (KOH) is 1:2. This means that for every 1 mole of sulfuric acid, we will need 2 moles of potassium hydroxide.
Given:
Volume of sulfuric acid (H2SO4) = 23.8 mL
Concentration of sulfuric acid (H2SO4) = 2.0 mol/L
Volume of potassium hydroxide (KOH) = 68.0 mL
Step 1: Convert volumes to liters
Volume of sulfuric acid (H2SO4) = 23.8 mL = 23.8 mL ÷ 1000 mL/L = 0.0238 L
Volume of potassium hydroxide (KOH) = 68.0 mL = 68.0 mL ÷ 1000 mL/L = 0.068 L
Step 2: Calculate the amount (in moles) of sulfuric acid using the concentration and volume
Amount of sulfuric acid (H2SO4) = concentration × volume
Amount of sulfuric acid (H2SO4) = 2.0 mol/L × 0.0238 L = 0.0476 moles
Step 3: Use the stoichiometric ratio to find the amount of potassium hydroxide (KOH)
According to the balanced equation, the ratio between sulfuric acid and potassium hydroxide is 1:2.
So, the amount of potassium hydroxide (KOH) is 2 times the amount of sulfuric acid (H2SO4).
Amount of potassium hydroxide (KOH) = 2 × 0.0476 moles = 0.0952 moles
Step 4: Calculate the concentration of potassium hydroxide (KOH)
Concentration of potassium hydroxide (KOH) = Amount of potassium hydroxide / Volume of potassium hydroxide
Concentration of potassium hydroxide (KOH) = 0.0952 moles / 0.068 L = 1.4 mol/L
Therefore, the concentration of potassium hydroxide in the given solution is 1.4 mol/L.