From a laboratory process designed to separate water into hydrogen and oxygen gas, a student collected 11.6 g of hydrogen and 65.9 g of oxygen. How much water was originally involved in the process?

don't understand how to work it out

This problem has the same trouble as in your other post below. It is SUPPOSED to be

water ==> hydrogen + oxygen
? .........11.6.......69.5
So water SHOULD be 11.6 + 69.5 but I get a different number if I work it a different way. I should get the same number both ways. That tell me that person making the problem just made up numbers.

To solve this problem, we can use the concept of stoichiometry and the law of conservation of mass. In the process of separating water into hydrogen and oxygen gas, we assume there is no loss of mass, meaning the total mass of the products should be equal to the original mass of water.

First, we need to determine the molar masses of hydrogen (H2) and oxygen (O2) gases. The molar mass of hydrogen is 2 g/mol (2 hydrogen atoms at 1 g/mol each), while the molar mass of oxygen is 32 g/mol (2 oxygen atoms at 16 g/mol each).

Next, we can calculate the number of moles for each gas using their respective masses. To find the number of moles, divide the mass of the substance by its molar mass.

Number of moles of hydrogen = Mass of hydrogen / Molar mass of hydrogen
Number of moles of hydrogen = 11.6 g / 2 g/mol

Number of moles of oxygen = Mass of oxygen / Molar mass of oxygen
Number of moles of oxygen = 65.9 g / 32 g/mol

By using these calculations, we find that there are 5.8 moles of hydrogen and 2.1 moles of oxygen.

Since the chemical formula for water is H2O, we know that 2 moles of hydrogen are required for every 1 mole of oxygen in water. By looking at the ratio of the moles of hydrogen to oxygen, we can determine the actual number of moles of water involved in the process.

Ratio of moles of hydrogen to moles of oxygen = 5.8 moles H2 / 2.1 moles O2

Simplifying this ratio, we see that the ratio is approximately 2.76 moles of hydrogen to 1 mole of oxygen.

Therefore, the number of moles of water can be calculated by dividing the number of moles of oxygen by the ratio:

Number of moles of water = Number of moles of oxygen / Ratio
Number of moles of water = 2.1 moles O2 / 2.76

By simplifying this calculation, we find that there are approximately 0.76 moles of water involved in the process.

Finally, to determine the mass of water, we can multiply the number of moles of water by its molar mass:

Mass of water = Number of moles of water * Molar mass of water
Mass of water = 0.76 moles * 18 g/mol (molar mass of water)

Rounding to significant figures, the mass of water originally involved in the process is approximately 13.7 g.