Question

При пропускании смеси метана и ацетилена объемом 8,96 л (н.у.) через склянку с бромной водой масса склянки увеличилась на 7,8 г. Определите объемную долю (в %) метана в исходной смеси.

Answer 1

Calculation of the Volume Fraction of Methane in the Mixture

To determine the volume fraction of methane in the initial mixture, we can use the information provided about the change in mass of the flask after passing the methane and acetylene mixture through bromine water.

Let's assume the volume of methane in the mixture is V1, and the volume of acetylene is V2. Since the total volume of the mixture is given as 8.96 L, we can write:

V1 + V2 = 8.96 L (Equation 1)

We are also given that the mass of the flask increased by 7.8 g after passing the mixture through bromine water. This increase in mass is due to the reaction of bromine with acetylene, forming a compound that adds to the mass of the flask. Since methane does not react with bromine, the increase in mass is solely due to the acetylene present in the mixture.

Now, let's assume the density of acetylene is ρ2 g/L. The mass of acetylene in the mixture can be calculated as:

Mass of acetylene = V2 * ρ2 (Equation 2)

Since the increase in mass is given as 7.8 g, we can write:

V2 * ρ2 = 7.8 g (Equation 3)

To find the volume fraction of methane, we need to calculate the volume of acetylene (V2) and then subtract it from the total volume of the mixture (8.96 L).

Let's solve the equations to find the volume fraction of methane:

From Equation 3, we can express V2 in terms of ρ2:

V2 = 7.8 g / ρ2 (Equation 4)

Substituting Equation 4 into Equation 1, we get:

V1 + (7.8 g / ρ2) = 8.96 L (Equation 5)

Now, we need to find the value of ρ2 to solve Equation 5. Unfortunately, the density of acetylene is not provided in the given information or search results. Without this information, it is not possible to calculate the volume fraction of methane accurately.

Therefore, we need additional information, such as the density of acetylene, to determine the volume fraction of methane in the initial mixture.

Please provide the density of acetylene, and I will be happy to assist you further.