4) How many grams of F2, gas occupy 4.9 L at STP?

We know two equations that can help as

n = m/Mr

n = V/Vm

So, combining the two equations above:

m/Mr = V/Vm

m = V×Mr/Vm

m = 8.31 gr

*To calculate the Mr of "F2" we need to multiply by 2 the atomic mass of F, which we can find onlu by looking it up in a table (probaly in the back of a chemistry book, or online). We see that it is equal to 19, so Mr will be equal to 38.

**The equations are derived easily. Lets take for example the first one. 1 mole of the substance contains Mr gr of it. So, how many gr do "n" moles contain?

8.31g

Explanation:

First, we calculate the molar mass of F2.

MM of F2 = 2 x 19 = 38g/mol

But,

1mol of a gas occupy 22.4L at stp.

This implies that 1mole(i.e 38g) of F2 occupies 22.4L.

Therefore, Xg of F2 will occupy 4.9L i.e

Xg of F2 = (38 x 4.9) / 22.4

Xg of F2 = 8.31g

Therefore 8.31g of F2 occupies 4.9L

the answer is yes

it has kinetic energy

reason

an object has kinetic energy when you stop the force carrying it, the object will stay in motion.

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