# chem help?

A balloon whose volume is 5.0 L contains 6.1 g of N2. What mass of N2 must be added to the balloon to expand its volume to 11 L at the same temperature and pressure?

### 5 Answers

- Dr WLv 72 months agoFavorite Answer
ideal gas law

.. P1V1 / (n1T1) = P2V2 / (n2T2)

since P and T are constant.. P1=P2 and T1=T2 so they drop out

.. V1 / n1 = V2 / n2

since n = mass / mw and since it's all N2 here

.. V1 / (m1/mw) = V2 / (m2/mw)

.. V1 / m1 = V2 / m2

.. m2 = m1 * (V2 / V1)

and we want mass added = m2 - m1,

.. mass added = m2 - m1 = m1 * (V2 / v1) - m1

.. .. .. .... ... ..... = m1 * (V2/V1 - 1) = 6.1g * (11L / 5.0L - 1) = 7.3g

- 1 month ago
A solution containing equal masses of glycerol ( C8H8O3) and water has a density of 1.10g/mol. Calculate the following.

A. Modality of glycerol in the solution

B. Mole fraction of glycerol in the solution

C. Molarity of glycerol in the solution

With solutions please.

- Roger the MoleLv 72 months ago
(6.1 g N2) x (11 L / 5.0 L) = 13.42 g N2 total

(13.42 g total) - (6.1 g initially) = 7.3 g N2 to be added

- Anonymous2 months ago
I don't think that's it

- How do you think about the answers? You can sign in to vote the answer.
- KennyBLv 72 months ago
We can reduce the ideal gas law elation to just the ration of moles and volume -- and since the mass of a mole of N2 is also c instant. we can remove mopes and replace it with grams. Then V1/g1 =V2/g2 and solve for g2

g2 = (6.1 g)11L/5L.

I get 13 g (to two significant figures)