Flashcards in Ch. 3.3 : Moles and Volumes Deck (14):

1

## What is the equation that links concentration , miles and volumes ?

### Moles = concentration x volume

2

## What is concentration ? Units?

### The amount of solute , in moles , dissolved in each dm3 of solution. Mol dm^-3

3

## How do you work out how much a certain solution is required to prepare a certain volume of a solution with a known concentration?

###
1. Work out the amount in moles required. Moles = concentration x volume

2. Work out the molar mass of the solution with the unknown concentration

3. Re arrange moles = mass / molar mass to calculate the mass of the solution

4

## What is molar gas volume ?

### The volume per mole of gas molecules at a stated temperature and pressure. Vm.

5

## What is RTP? What is molar gas volume at RTP?

###
Room temperature and pressure.

This is about 20°C and 101 kPa ( 1 atm)

At RTP, 1 mole of gas molecules has a volume of approximately 24dm3. Therefore molar gas volume = 24 dm^3 mol^-1

6

## How do you link moles, volume and molar gas volume ?

### Moles = volume / molar gas volume

7

## What is the ideal gas equation ?

###
pV = nRT

p = pressure ( Pa)

V = volume ( m3)

n = moles

R = ideal gas constant

T = temperature ( K )

8

## How can you rearrange the ideal gas equation to find moles?

### n= pV/ RT

9

## What are the assumptions made for the molecules making up an ideal gas?

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- random motion

- elastic collisions

- negligible size

- no intermolecular forces

10

## How do you calculate the relative molecular mass of something?

###
Convert all the quantities to match the ideal gas equation

Use the ideal gas equation to calculate the unknown

Find the molar mass ( using moles = mass / molar mass )

11

## How do you convert from cm3 to m3?

### Divide by 1000000

12

## How do you convert from dm3 to m3?

### Divide by 1000

13

## How do you convert from °C to K?

### + 273

14