Year 12s: what will be the first way you research your future options? >>

how do i get to understand chemistry in the easiest way posssible?

i have problems with moles.....molarity and i just want some help?

When calculating moles I always use this triangle formulae

Mass
-----------
RAM. l Moles. (Animals always go in the bottom)

Then when calculating molarity ( which is concentration I use this:

Moles
-----------------------
Conc. l volume

So which ever one you need to find, just cover it eg finding the moles
The equation would be:
Moles= mass/ ram or
Moles = conc x volume

Posted from TSR Mobile

(edited 10 years ago)

Reply 2

joostan

Original post by +jazmin

i have problems with moles.....molarity and i just want some help?

First off, welcome to TSR :tsr:

Second, the above poster has some excellent advice on mole calculations - though if it's another problem with moles I'd be happy to help :smile:

I've taken the liberty of texing up a few of the equations -it seems neater.

\mathrm{Mass}= \mathrm{M_r} \times \mathrm{Moles}[br]\mathrm{Concentration} = \dfrac{\mathrm{Moles}}{\mathrm{Volume (\mathrm{in} \ dm^3)}}

If the volume is in

cm^3

Then:

1dm^3=1000cm^3

(edited 10 years ago)

Reply 3

Davelittle

If you need help with anything other than what has been posted above please quote me or PM me and I'll be happy to help. :smile:

(edited 10 years ago)

Reply 4

Dynamo123

Same as Davelittle. :smile:

Reply 5

charco

Study Forum Helper

Original post by +jazmin

i have problems with moles.....molarity and i just want some help?

There are a whole series of videos on moles on the Colourful Solutions Youtube site

Reply 6

dynamicmind

The mole is the unit denotes amount i.e. 1 mole equals to 6.0×10-2

Posted from TSR Mobile

Reply 7

dynamicmind

I mean 10 -23 shows amount.

Posted from TSR Mobile

Reply 8

dynamicmind

While molarity is the potency, as 2/ normality.

Posted from TSR Mobile

Reply 9

dynamicmind

If u again want any info u cn text me.

Posted from TSR Mobile

Reply 10

Kallisto

Entertainment Forum Helper

Original post by +jazmin

i have problems with moles.....molarity and i just want some help?

moles = molarity - that was a nice blooper. :biggrin:

Joke aside! did you mean the calculation of molarity? Or with the definition of one?. I give an answer for both questions. It is the concentration of a chemical substance in a solution. The molarity (c) is the quotient of amount of a substance (n) and the volume (V) of it: c = n/V. As you can see the molarity depends on the amount of the substance and the Volume in relation.

The amount of a substance consist of mass (m) of a chemical substance/element and the molar mass (M) of this one.
It is the quotient n = m/M. In this case the amount of the substance depends on the mass and the molar mass.

(edited 10 years ago)

Reply 11

saurabhrai

Mole is equivalent to the Avogadro Number which has a value of 6.022×10²³elementary entities of the substance. Consider this example
2 H₂ + O₂ → 2 H₂O implies that 2 mol of H₂ and 1 mol of O₂ react to form 2 mol of H₂O.

Whereas Molarity is defined as the number of moles of solute dissolved in 1 liter of solution. Lets take an example:

We find molarity of a solution that contains 10.0g of HCl (molar mass 36.5g/mol) per liter of solution

Number of moles of HCl equivalent to 10.0g of HCl.

10.0g HCl × 1 mol HCl36.5g HCl = 0.274 mol HCl

With 0.274mol/lt the molarity is 0.274M in HCl.