Question

How many grams of hydrogen gas are produced upon complete reaction of 4.6 moles of sodium with water? sodium oxide is the other product.

Answer 1

Well firstly lets write the equation out. So we know that sodium (Na) and water (H2O) react and make hydrogen gas (H2). As stated in the question the other product formed is apparently sodium oxide (Na2O), so we can use this to write it out. The balanced equation would be this:

2 Na + H2O ----> Na2O + H2

So we know we have 4.6 mol of sodium to react with water. To work out the mass of hydrogen gas produced, we will need to find the moles of hydrogen gas.

As there are 2 moles of sodium (as you can see there is a 2 in front of Na) that means our answer of mol is for TWO moles of sodium, however hydrogen gas has no number in front of it, meaning there is only ONE mole of the substance. This means we will have to divide our answer by 2 to get the answer of moles for 1 mol (as right now, our answer is for 2 moles).

4.6 / 2 = 2.3 mol of H2

Now we have to find the grams of hydrogen gas produced. We can do that by using this equation: mass = moles x molar mass (Molar mass of H2 is 2)

2.3 x 2 = 4.6g of H2 is produced

So your answer is 4.6g of hydrogen gas. I hope this helped!