Question

10- volume \(\mathrm{H}_{2} \mathrm{O}_{2}\) is equivalent to: (1) \(10 \%\) (2) \(30 \mathrm{~g} / \mathrm{L}\) (3) \(1.786 \mathrm{~N}\) (4) \(3 \% \mathrm{H}_{2} \mathrm{O}_{2}(\mathrm{~W} / \mathrm{V})\) (a) \(1,2,3\) (b) \(1,2,4\) (c) \(2,3,4\) (d) 2,4

Short answer

The answer is (c) 2,3,4.

Step-by-step solution

Understanding 10-volume H2O2

The term '10-volume' means that 1 volume of hydrogen peroxide (H2O2) will decompose to give 10 volumes of oxygen gas (O2) under standard conditions. This measurement is a way to express the concentration of hydrogen peroxide based on the volume of oxygen it can produce.

Finding the weight/volume percentage

To express the concentration of hydrogen peroxide in percentage (W/V), we need to understand how much hydrogen peroxide is required to produce that volume of oxygen. 10-volume H2O2 is approximately equivalent to 3% of hydrogen peroxide by weight/volume because it produces 10 volumes of oxygen from 1 volume of the solution.

Determining g/L concentration

10-volume H2O2 can also be considered to contain about 30 g/L. This quantification is based on the typical relationship between volume strength and molarity or mass concentration, with 10-volume often corresponding to a 3% solution by weight/volume, translating to approximately 30 g/L.

Evaluating Normality

The normality (N) of a hydrogen peroxide solution can be estimated based on its decomposition to oxygen. A 10-volume solution is approximately 1.786 N, as derived from the relation between volume strength and normality.

Verifying against options

From the calculations above, 10-volume hydrogen peroxide is equivalent to a 3% W/V solution, or approximately 30 g/L. There is also a correlation to about 1.786 N based on its ability to furnish oxygen. These correlations match options (2), (3), and (4).

Key concepts

Concentration Measurement

Concentration measurement is a crucial concept in chemistry as it defines how much of a substance is present in a given volume. When dealing with hydrogen peroxide (H\(_2\)O\(_2\)), the concentration can be measured using various methods. One common way to express the concentration of a solution is through volume strength, which describes the volume of gas that can be released from the solution under standard conditions. In the case of hydrogen peroxide, a '10-volume' solution means that 1 volume of the solution will produce 10 volumes of oxygen gas. This indicates the possible amount of gas that can be released, giving a unique method to quantify concentration that you won't find in more routine measurements like mass per volume or molarity. Understanding how much of a component is present aids in determining the usability and potency of solutions in chemical reactions and processes.

Normality

Normality is another method used to express concentration, often applied in titration reactions in chemistry. It accounts not just for the amount of solute in a solution but also the valence of the solute, or the amount of it that participates in the reaction. In the context of hydrogen peroxide, normality can help indicate the concentration based on its ability to decompose and release oxygen. For a 10-volume hydrogen peroxide solution, the normality is approximately 1.786 N. This is calculated by correlating the volume strength with normality, understanding its potential to release gas, and contributing equivalently in reactions like oxidations or reductions. Normality is particularly useful for reactions involving ions or where equivalent amounts of reactants are involved.

Weight/Volume Percentage

Weight/volume percentage (W/V %) is a straightforward way to express solution concentration by representing the mass of solute in a given volume of solution, generally in grams per 100 mL. When considering 10-volume hydrogen peroxide, it approximately equates to a 3% weight/volume percentage. This value is derived from the relationship between how much oxygen is produced per unit volume of hydrogen peroxide. Weight/volume percentage is advantageous because it allows for an intuitive understanding of how concentrated a solution is from a mass perspective. This is commonly used in medical and chemical settings, where it provides an easy way to prepare solutions at required strength levels.

Gas Volume Measurement

In chemistry, gas volume measurement is often a means to express the concentration of solutions capable of releasing gases through chemical reactions or decomposition. For hydrogen peroxide, understanding its concentration in terms of gas volume involves the "volume strength" measurement, as it describes how many volumes of oxygen are produced from a single volume of solution. This measurement is essential in practical scenarios, where the amount of gas released by a reaction has ramifications for safety, effectiveness, and environmental impacts. A 10-volume strength indicates that decomposition of hydrogen peroxide releases 10 times the gas volume, making it a potent and calculable reactant in various chemical processes.