Question

Как избавиться от пятен на белой ткани? Пятно смачивают водой, затем посыпают порошком гидросульфита натрия, потом пипеткой наносят на него 3%-ный водный раствор пероксида водорода. После этого промывают обработанное место водой с добавкой уксуса. Выделяющиеся атомарный кислород и газообразный диоксид серы эффективно обесцвечивают любые пятна. Рассчитайте объем (н.у.) газов, которые выделяются при использовании 1 мл 3%-го раствора пероксида водорода (практический выход реакции 70%) и 0,5 г гидросульфита натрия (практический выход реакции 85%). Плотность раствора пероксида водорода равна плотности воды.

Answer 1

Попытайся замочить и тогда  пятнышко исчезнит))

Answer 2

Removing Stains from White Fabric

To remove stains from white fabric, you can follow a specific process that involves using water, sodium hydrosulfite powder, and a 3% hydrogen peroxide solution. Here are the steps:

1. Dampen the stained area with water. 2. Sprinkle sodium hydrosulfite powder on the stain. 3. Using a dropper, apply a 3% hydrogen peroxide solution to the powder. 4. Afterward, rinse the treated area with water mixed with vinegar.

The atomic oxygen and gaseous sulfur dioxide released during this process effectively bleach any type of stain.

Calculating the Volume of Gases Produced

To calculate the volume of gases produced when using 1 ml of a 3% hydrogen peroxide solution (with a practical reaction yield of 70%) and 0.5 g of sodium hydrosulfite (with a practical reaction yield of 85%), we need to know the molar masses of hydrogen peroxide (H2O2) and sodium hydrosulfite (Na2S2O4).

The molar mass of hydrogen peroxide (H2O2) is approximately 34 g/mol, and the molar mass of sodium hydrosulfite (Na2S2O4) is approximately 174 g/mol.

Using the given amounts and molar masses, we can calculate the number of moles of each substance:

- Hydrogen peroxide (H2O2): - Mass = 1 ml * 3% * 1 g/ml = 0.03 g - Moles = 0.03 g / 34 g/mol = 0.000882 mol

- Sodium hydrosulfite (Na2S2O4): - Moles = 0.5 g / 174 g/mol = 0.002874 mol

Since the balanced chemical equation is not provided, we cannot determine the exact stoichiometry of the reaction. However, assuming a simple reaction, we can estimate the volume of gases produced based on the number of moles of each substance.

Considering that gases occupy 22.4 liters per mole at standard temperature and pressure (STP), we can calculate the volume of gases produced:

- Hydrogen peroxide (H2O2): - Volume = 0.000882 mol * 22.4 L/mol = 0.0197 L (or 19.7 ml)

- Sodium hydrosulfite (Na2S2O4): - Volume = 0.002874 mol * 22.4 L/mol = 0.0644 L (or 64.4 ml)

Please note that these calculations are approximate and based on several assumptions. The actual volume of gases produced may vary depending on the specific reaction conditions and stoichiometry.