Question

При действие серной кислоты (избыток) на смесь цинка с медью массой 19,4 г. выделится водород объёмом (при н.у) 0,00448 м .Рассчитайте массовую долю меди в смеси.

Answer 1

Реакция идет только с циником => zn+h2so4=znso4+h2 находим химическое кол-во h2 для этого переводим м^3 в дм^3 и находим n(h2)=4.48/22.4=0.2 составляем пропорция и получаем хим.кол-во цинка n(zn)=0.2mol m(zn)=0.2*65=13g далее находим массую долю меди (19.4-13)/19.4*100%=33%

Answer 2

Calculating the Mass Fraction of Copper in the Mixture

To calculate the mass fraction of copper in the mixture, we can use the information provided about the reaction between excess sulfuric acid and a mixture of zinc and copper.

Given: - Mass of the mixture (zinc and copper) = 19.4 g - Volume of hydrogen gas evolved at standard conditions = 0.00448 m³

First, we need to find the amount of copper in the mixture. Then, we can calculate the mass fraction of copper.

Step 1: Calculate the Amount of Copper in the Mixture

The reaction between sulfuric acid and the mixture of zinc and copper can be represented as follows: ``` Cu + H2SO4 → CuSO4 + H2 ```

From the given volume of hydrogen gas evolved, we can calculate the number of moles of hydrogen gas using the ideal gas law. Then, we can use the stoichiometry of the reaction to find the moles of copper involved in the reaction.

Step 2: Calculate the Mass Fraction of Copper

Once we have the moles of copper involved in the reaction, we can calculate the mass of copper and then determine its mass fraction in the mixture.

I will now proceed with the calculations based on the provided information.