Question

Помогите срочно нужна помощь помогите. На смесь цинка с серебром массой 127,5г подействовали серной кислотой. При этом выделилось 2,24 л (н.у.) водорода. Определите массовую долю серебра в смеси.

Answer 1

Ответ:

94,9%

Объяснение:

Answer 2

Calculation of the Mass Fraction of Silver in the Mixture

To determine the mass fraction of silver in the mixture, we need to calculate the mass of silver and the total mass of the mixture.

Given: - Mass of the mixture (zinc + silver) = 127.5 g - Volume of hydrogen gas evolved = 2.24 L (at standard temperature and pressure)

To calculate the mass of silver, we need to find the moles of hydrogen gas evolved. The volume of hydrogen gas can be converted to moles using the ideal gas law. The molar volume of any gas at standard temperature and pressure (STP) is 22.4 L/mol.

Using the equation: n = V / Vm

where: - n is the number of moles of hydrogen gas - V is the volume of hydrogen gas evolved (2.24 L) - Vm is the molar volume of gas at STP (22.4 L/mol)

Let's calculate the number of moles of hydrogen gas evolved:

n = 2.24 L / 22.4 L/mol n = 0.1 mol

Since the reaction between zinc and sulfuric acid is a 1:1 ratio, the number of moles of silver is also 0.1 mol.

Now, we can calculate the mass of silver using its molar mass. The molar mass of silver (Ag) is approximately 107.87 g/mol.

Mass of silver = number of moles of silver * molar mass of silver Mass of silver = 0.1 mol * 107.87 g/mol Mass of silver = 10.787 g

To find the mass fraction of silver in the mixture, we divide the mass of silver by the total mass of the mixture and multiply by 100.

Mass fraction of silver = (mass of silver / mass of mixture) * 100 Mass fraction of silver = (10.787 g / 127.5 g) * 100 Mass fraction of silver ≈ 8.46%

Therefore, the mass fraction of silver in the mixture is approximately 8.46%.