Question

A 4.236-g sample of a mixture containing only Cu2O and CuO was treated with hydrogen to produce 3.677 g of pure copper metal. Calculate the percentage composition (by mass) of the mixture.

Percent of Cu2O
Percent of CuO

Answer 1

To calculate the percentage composition (by mass) of the mixture containing Cu2O and CuO, set up a system of equations using the given information. Solve the system to find the masses of Cu2O and CuO, then calculate the percentage composition.

Step-by-step explanation:

To calculate the percentage composition (by mass) of the mixture, we need to determine the masses of Cu2O and CuO in the mixture. Let's assume the mass of Cu2O is x g and the mass of CuO is y g.

From the given information, we know that the total mass of the mixture is 4.236 g. Therefore, we have the equation:

x + y = 4.236

After treating the mixture with hydrogen, we obtain 3.677 g of pure copper metal, which means the total mass of Cu2O and CuO reduced to form the copper metal is:

x + y - 3.677 = 0

Now, we have a system of two equations with two variables. Solving these equations will give us the values of x and y, which represent the masses of Cu2O and CuO, respectively. Once we have the masses, we can calculate the percentage composition (by mass) by dividing the individual masses by the total mass of the mixture and multiplying by 100.

Answer 2

To calculate the percentage composition of the mixture, we need to determine the masses of Cu2O and CuO in the mixture. The mass of Cu2O is 0.559 g and the mass of CuO is 3.677 g. The percentage composition of Cu2O is 13.2% and the percentage composition of CuO is 86.8%.

Step-by-step explanation:

To calculate the percentage composition of the mixture, we need to determine the masses of Cu2O and CuO in the mixture. Let's assume the mass of Cu2O is x and the mass of CuO is y. Since the sample contains only Cu2O and CuO, we can write the following equation: x + y = 4.236 g

When the sample is treated with hydrogen to produce pure copper metal, the mass of the mixture decreases to 3.677 g. The reaction can be represented as Cu2O + H2 -> Cu + H2O. Since Cu2O is reduced to Cu, the mass of Cu2O is converted to pure copper metal. So x g of Cu2O is converted to x g of copper metal. The mass of CuO that remains is (4.236 - x) g.

According to the information given, the mass of copper metal produced is 3.677 g. So we can write another equation: x + (4.236 - x) = 3.677 g. Simplifying this equation, we find x = 0.559 g. Therefore, the mass of Cu2O is 0.559 g and the mass of CuO is 4.236 - 0.559 = 3.677 g.

To calculate the percentage composition, we divide the mass of each component by the total mass of the mixture and multiply by 100. The percentage composition of Cu2O is (0.559 g / 4.236 g) x 100% = 13.2%. The percentage composition of CuO is (3.677 g / 4.236 g) x 100% = 86.8%.