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...

Balancing equations

When a reaction occurs there are two main elements in this: The reactants and the products . It is simply a matter of being aware of your elements and their groups, electrons and a little bit of simple brain twisting! Before we begin, it is important you know and understand these symbols and its just a matter of either you know it or you don't! (s)- Solid (l)- Liquid (g)- Gaseous (aq)- Aqueous Now lets try some simple equations! For ease and simplicity lets start from the bottom with H2O, now what do we know about this substance? Yup its that's flavourless thing that comes out of your tap which let be honest no one enjoys unless its with juice, tea or a hot chocolate. If you understand this just skip ahead, wouldn't want to waste your tyme ;) So water, let get it into its equation form: H2 + O2 ----> H2O So what the problem here? Did you spot it? Its unbalanced, every chemists nightmare! So how do we solve ...

Intermolecular Forces

Intermolecular forces So intermolecular forces what are they all about?! In plain English, intermolecular forces are the smaller forces in a bigger equation and are simply forces between molecules. You can get a range of different bonds, the main ones we know are ionic and covalent bonds which are very strong when compared to these little intermolecular forces in between molecules. There are three different intermolecular forces you deal with at A level and trust me these little guys will become the bane of your life. These three types of bonds are known as hydrogen bonding, permanent dipoles and temporary dipoles. Hydrogen bonding Hydrogen bonding is the strongest type of intermolecular force and occurs in molecules containing a O-H, N-H or F-H bonds, this is due to oxygen, nitrogen and fluorine being the most electronegative elements which then creates something known as a dipole. These dipoles exist as delta negative and delta positive and refers the the distribution of e...

A level Chemistry

Search This Blog