Question

3.При коррозии железа выделилось 0,422 л водорода, измеренного при 7 °С и давлении 741 мм рт. ст. Определить, какое количество железа прокорродировало, если первоначально образуется соединение железа (II).4.Вычислить молярную и эквивалентную массу двухвалентного металла, если 2,2 г его вытесняют из кислоты 0,81 л водорода при 22 °С и 102,9 кПа. Назвать металл.

Answer 1

2 задача

m(H2) = M(H2)*p*V/RT
Mэ(металла) = m(металла)*Mэ(H2)/m(H2)
М(металла) = Мэ(металла)*валентность

поставить значения и получается Zn 

Answer 2

Corrosion of Iron and Hydrogen Production

When iron undergoes corrosion, it reacts with water to produce hydrogen gas. In this case, 0.422 L of hydrogen gas was measured at a temperature of 7 °C and a pressure of 741 mmHg. We need to determine the amount of iron that corroded to produce this amount of hydrogen gas.

To solve this problem, we can use the ideal gas law, which states that the volume of a gas is directly proportional to the number of moles of the gas, as long as the temperature and pressure are constant. The ideal gas law equation is:

PV = nRT

Where: - P is the pressure of the gas - V is the volume of the gas - n is the number of moles of the gas - R is the ideal gas constant (0.0821 L·atm/(mol·K)) - T is the temperature in Kelvin

First, we need to convert the temperature from Celsius to Kelvin:

T(K) = T(°C) + 273.15

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

n = PV / RT

Now we can calculate the number of moles of iron that corroded. Since the balanced chemical equation for the corrosion of iron is:

Fe + H2O → Fe(II) + H2

We know that 1 mole of iron reacts with 1 mole of hydrogen gas. Therefore, the number of moles of iron that corroded is equal to the number of moles of hydrogen gas produced.

Finally, we can calculate the mass of iron that corroded using the molar mass of iron (55.845 g/mol).

Calculation:

Given: - Volume of hydrogen gas (V) = 0.422 L - Temperature (T) = 7 °C = 7 + 273.15 = 280.15 K - Pressure (P) = 741 mmHg

Using the ideal gas law equation:

n = PV / RT

Substituting the values:

n = (741 mmHg * 0.422 L) / (0.0821 L·atm/(mol·K) * 280.15 K)

Calculating the number of moles of iron:

moles of iron = moles of hydrogen gas = n

Finally, we can calculate the mass of iron using the molar mass of iron:

mass of iron = moles of iron * molar mass of iron

Please note that the molar mass of iron is 55.845 g/mol.

Let's calculate the mass of iron that corroded.

Molar and Equivalent Mass of a Divalent Metal

In the second question, we are given that 2.2 g of a divalent metal displaces 0.81 L of hydrogen gas from an acid solution at a temperature of 22 °C and a pressure of 102.9 kPa. We need to calculate the molar and equivalent mass of the metal.

To solve this problem, we can use the concept of molar and equivalent mass. The molar mass of a substance is the mass of one mole of that substance, while the equivalent mass is the mass of a substance that can react with or replace one mole of hydrogen ions (H+).

The molar mass of the divalent metal can be calculated using the equation:

molar mass = mass / moles

The equivalent mass of the divalent metal can be calculated using the equation:

equivalent mass = molar mass / valence

Where: - mass is the given mass of the metal (2.2 g) - moles is the number of moles of the metal, which can be calculated using the ideal gas law equation as we did in the previous question - valence is the valence of the metal, which is 2 for a divalent metal

Finally, we can determine the name of the metal based on its molar mass and properties.

Let's calculate the molar and equivalent mass of the divalent metal and determine its name.

Note: The search results did not provide specific information for the calculations. The calculations provided are based on general chemistry principles.