Question

ПОЖАЛУЙСТА РЕБЯТ.Какой объем водорода может быть получен при растворении в воде 1,4 грамма кальция??????

Answer 1

Пишешь уравнение реакции:

Ca+2H2O=Ca(OH)2+H2

Находишь количество кальция:

n(Ca)=m/M=1,4/40=0,035 моль

Составляешь пропорцию. над кальцием в уравнении реакции пишешь 0,035 моль, внизу 1; под водородом пишешь 1 а сверху - x. получается пропорция:

0,035моль/1=x/1

x=0,035 моль

n(H2)=0,035 моль

Теперь находишь обйем водорода, умножая его количество на Vm=22,4 л. 

V(H2)=0,784 л

 

Answer 2

Calculating the Volume of Hydrogen Produced from the Dissolution of Calcium in Water

To calculate the volume of hydrogen produced when 1.4 grams of calcium is dissolved in water, we can use the chemical equation for the reaction and the ideal gas law.

The chemical equation for the reaction of calcium with water is: Ca + 2H2O → Ca(OH)2 + H2

From the balanced chemical equation, we can see that 1 mole of calcium reacts with 2 moles of water to produce 1 mole of hydrogen gas.

Using the molar mass of calcium and the ideal gas law, we can calculate the volume of hydrogen gas produced.

Calculation Steps

1. Calculate the moles of calcium: - The molar mass of calcium (Ca) is approximately 40.08 g/mol. - Therefore, the moles of calcium can be calculated as: ``` moles of Ca = mass of Ca / molar mass of Ca = 1.4 g / 40.08 g/mol ≈ 0.035 moles ```

2. Calculate the moles of hydrogen: - From the balanced chemical equation, 1 mole of calcium produces 1 mole of hydrogen gas. - Therefore, the moles of hydrogen produced will be the same as the moles of calcium, which is approximately 0.035 moles.

3. Apply the ideal gas law to calculate the volume of hydrogen: - The ideal gas law is given by the equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin. - Assuming standard temperature and pressure (STP), where T = 273.15 K and P = 1 atm, and using the value of the gas constant R = 0.0821 L·atm/(K·mol), we can calculate the volume of hydrogen: ``` V = nRT / P = (0.035 moles)(0.0821 L·atm/(K·mol))(273.15 K) / 1 atm ≈ 0.81 L ```

Conclusion

When 1.4 grams of calcium is dissolved in water, approximately 0.81 liters of hydrogen gas can be produced at standard temperature and pressure (STP).