Moles and gas volumes

This is similar to amount of substance, however we are working with gases and gas volumes alone. This works effectively when the substance is held at RTP.

When the volume is in cm cubed the equation is:

n=V/24000       n=Moles
                         V=volume
                         As for the 24,000 just don't question it! If that's what they want, that's what they'll get!

As usual we will go through some examples step by step. However, one thing you do need to know is RTP meaning room temperature and pressure.

What amount, in mol, of gas molecules is in 72 cm cubed of any gas at RTP?

This is simply plugged in:

n=72/24,000= 0.0030 moles

Now lets try something a little more brain tingling:

What is the volume in, cm cubed, of 2.130 x 10 to the power of negative 3 mol of a gas at RTP?

Once again we plug in the info we posses into the formula:

2.130 x10 neg 3=V/24000

We now need to rearrange this to form:

V= 2.130 x 10 neg 3 x 24,000= 51.12 cm cubed

It's just applying what information you posses and plugging it into the formula effectively! Do this with your question and you're cooking with gas!

Till next tyme! :)

Comments

Electrons and orbitals

So everything you were taught at GCSE by your teachers, yeah that was all a lie, completely forget that they lied to you! Electron shells aren't flat they are 3D and that issue with going past 20 electrons? Fret no more because we can now get past this, admittedly with a lot of work but what doesn't kill you makes you stronger! So these electron orbitals are filled with sub levels, remember the 2.8.8.2 formula? Well it turns out they were actually sub levels in an atom, here take a look: As you can see the shells are known as 'n' and the number of that orbital increases the further away it gets. Now not to confuse you but technically they are all on top of each other and the distance between each of these is miniscule! When drawing them though I recommended giving them space otherwise you are not going to be working with a lot! So lets take a deep look at this: Orbitals are known as S, P, D, F and so on but you don't really need to know any further for now. No

Bonding

Now back to basics I know but its surprising how the simple stuff can catch you out! So lets get this party started: Electrons - have a negative charge and is equal to that of protons Protons - have positive charges and can be found as the smaller number under an element. Neutrons - has a neutral charge and is found out by taking the atomic mass (smaller number) away from the relative atomic mass (the bigger number) Some atoms are quite happy to stay on their tod without any need of bonding, these are known as 'noble gases'. These elements make up the group 0/8 on the periodic table and this purely means their outer shell is full of electrons so there is no need for any actual bonding to occur. Being that their outer shell is full they are extremely stable elements and almost never react because of this. However, as the group number decreases the less stable an element is, making group 1 very unstable. There are 3 types of bonding and as you have probably guessed they a

A level Chemistry

Search This Blog