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A. Commercial hydrogen peroxide (H2O2) solutions are explosively decomposed by traces of transition metal ions such as manganese or iron. When peroxide decomposes it forms water and oxygen.

What volume of pure oxygen collected at 27 degrees C and 746 torrs would be generated by the decomposition of 125 g of a 50% by mass hydrogen peroxide solution?

b. If the water formed by this reaction condenses, what is the volume of the liquid water formed?

User Ifeoma
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Final answer:

The decomposition of hydrogen peroxide (H2O2) into water and oxygen can be calculated using stoichiometry and the ideal gas law. For 125 g of a 50% by mass hydrogen peroxide solution, 0.92 mol of oxygen gas would be generated. The volume of oxygen gas collected at 27 degrees C and 746 torrs would be approximately 92 mL. The volume of liquid water formed in the reaction would be 1.84 mL.

Step-by-step explanation:

The decomposition of hydrogen peroxide (H2O2) into water and oxygen can be represented by the following equation:

2H2O2 → 2H2O + O2

First, we need to calculate the number of moles of hydrogen peroxide present in the 125 g solution. To do this, we divide the mass by the molar mass of H2O2 (34.01 g/mol) and convert to moles. Mass of H2O2 = 125 g * 0.50 = 62.5 g. Moles of H2O2 = 62.5 g / 34.01 g/mol = 1.84 mol.

According to the stoichiometry of the reaction, 2 moles of H2O2 produce 1 mole of O2. Therefore, 1.84 moles of H2O2 will produce half as many moles of O2. Moles of O2 = 1.84 mol * (1 mol O2 / 2 mol H2O2) = 0.92 mol.

To calculate the volume of oxygen gas at 27 degrees C and 746 torr, we can use the ideal gas law equation: PV = nRT. Rearranging the equation to solve for V (volume), we have V = (nRT) / P. Plugging in the values, V = (0.92 mol * 0.0821 L * atm / K * mol * (27 + 273) K) / 746 torr = 0.092 L or 92 mL.

b. Since water is in liquid form, we need to calculate the volume of liquid water. From the stoichiometry of the reaction, we know that 2 moles of H2O are produced for every 2 moles of H2O2. Therefore, the moles of water produced will be equal to the moles of hydrogen peroxide. Moles of water = 1.84 mol. Now we can convert moles to volume using the density of liquid water (1 g/mL). Volume of water = 1.84 mol * 1 mL/mol = 1.84 mL.

User Ilianna
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