Life or Death !! Please help me!!

Question

I DONT KNOW WHAT TO DO IM TOTALLY LOST

Given the reaction

2No(g) O2(g) ----> 2No2(g)

if 6.5 L of O2 react at STP how many liters of No2 are produced??

Answer 1

Write the balanced equation-

2NO + O2 --> 2NO2

6.5 L O2 at STP --> 13.0 L NO2 at STP

You get 2 mol of NO2 for 1 mol of O2 and volume at STP is directly proportional to moles.

6.5 L of any (ideal) gas at STP = 6.5/22.4 mol = 0.290 mol

You will get 2 x 0.290 mol NO2

0.580 mol x 22.4 liters/mol = 13 liters NO2

  

Answer 2

you need to rewrite this problem 'No' is not an element.

Answer 3

This is stoichiometry. You are given the number of liters of gas at STP so you can find the number of moles of gas. Then using mole ratios and the chemical equation you can find the number of moles of NO2 that are produced from the given amount of oxygen.

The equation is:

2NO(g) + O2(g) --> 2NO2(g)

Convert the volume of O2 into moles. Remember for every gas at STP, one mole of gas occupies 22.4L.

6.5L *(mole/22.4L) = .290moles of O2

Use the mole ratio to convert moles of oxygen into moles of NO2. For every one mole of O2 used two moles of NO2 are produced.

.290moles of O2 *(2 mol of NO2/1 mol of O2) = .580moles of NO2

Now convert back to liters.

.580moles *(22.4L/mole) = 13L of NO2

Tips: Stoichiometery is just using mole ratios from a equation.

Now that I think about it you don't have to even convert to moles on this one because you convert back to volume. All you need is the mole ratio.

6.5L * (2 mol NO2/1 mol O2) = 13L NO2

See the 22.4 cancels out in this case.

Answer 4

2.63

Answer 5

one mole of an ideal gas occupies 22.4 liters in volume.  You have 6.5 liters of O2.  Start by finding out how many moles that is.  22.4 / 6.5 =  ~ 3,5 moles of O2.  So you'll end up with 7 moles of NO2.

Always convert every thing to moles; that's how it works.  The "mole concept".  Learn that.