chem help please

Question

f a 0.738 g block of sodium is placed in excess water, heat and a gas are produced. If the gas is at 276^oC and the atmospheric pressure that day is 0.927 atm, how many milliliters of gas is produced?

Answer 1

Hello, Molly,

Please post whatever portions of the problem you have already completed. There are a lot of steps here, so I'll need to be brief on the explanations. You've already covered stoich and the gas laws - this questions combines them. Start with a balanced equation:

2Na + 2H₂O = 2NaOH + H₂

The 0.738 grams of sodium amounts to 0.0314 moles of Na. The equation says we only get 1 mole of H₂ for every 2 moles of Na. So we'll wind up with 0.0157 moles of hydrogen gas.

Use the ideal gas law to find the volume, V, of this amount of gas at the conditions specified. Remember to convert C to K.

PV = nRT

(0.927atm)(V) = (0.0157moles)(0.082058L*atm*K^-1mole^-1)(549.15K)

I get Volume = 0.7643 liters

Bob