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Household hydrogen peroxide is an aqueous solution of hydrogen peroxide (H2O2), and its concentration is often measured as a percent by weight. Most drug stores sell 3% solution, which means there are 3.0 g of H2O2 per every 100 g total of solution (H2O2 H2O). For the kinetics experiment, 15 mL of 3% (w/w) hydrogen peroxide solution was poured into a measuring cup with 120 mL of water. 5 mL of 1M sodium carbonate solution (Na2CO3) was also added to the mixture. What is the molar concentration (molarity) of hydrogen peroxide (in mol/L) of the final solution

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maacastrobr

Answer:

0.093 M

Explanation:

First, we assume that the density of household hydrogen peroxide is 1 g/mL. We also assume that there's no reaction between hydrogen peroxide and sodium carbonate, if there were, in the end all hydrogen peroxide would be consumed.

Now we calculate how many grams of H₂O₂ were added, using the given volume, concentration and density:

  • 15 mL * [tex]\frac{1gSolution}{1mL}*\frac{3gH_2O_2}{100gSolution}[/tex] = 0.45 g H₂O₂

We convert grams to moles:

0.45 g H₂O₂ ÷ 34 g/mol = 0.013 mol H₂O₂

Now we divide the number of moles by the final volume, to calculate the molarity of H₂O₂:

  • Final Volume = 15 mL + 120 mL + 5 mL = 140 mL
  • 140 mL / 1000 = 0.140 L
  • Molarity = 0.013 mol H₂O₂ / 0.140 L = 0.093 M

mickymike92

Based on the given concentration of the original hydrogen peroxide solution, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.

What is the concentration of the hydrogen peroxide solution?

Assuming that the density of household hydrogen peroxide is 1 g/mL and that no reaction occurs between hydrogen peroxide and sodium carbonate.

The mass in grams of H₂O₂ added is first determined using the given volume, concentration and density:

  • mass = volume * density * concentration

mass = 15 mL *  1 g/mL * 3g/100g  = 0.45 g H₂O₂

Moles of H₂O₂ is determined as follows:

  • moles = mass /molar mass

molar mass of H₂O₂ = 34 g/mol

moles of H₂O₂ = 0.45 g H₂O₂ / 34 g/mol

moles of H₂O₂ = 0.013 mol H₂O₂

molarity of H₂O₂ is then calculated as follows:

  • molarity = moles/volume in L

final volume = 15 mL + 120 mL + 5 mL = 140 mL

final volume = 140 mL / 1000 = 0.140 L

molarity = 0.013 mol H₂O₂ / 0.140 L

molarity of H₂O₂ = 0.093 M

Therefore, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.

Learn more about molarity at: https://brainly.com/question/17138838

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