General calculation some are in types of reactions

Question 1

What is Ar?

Answer 1

Relative mass

4
ㅤ H
2

Question 2

What Is Mr?

Answer 2

Relative formula mass

eg: CO2
C= 12 O=16
16 x 2 = 32 32+12=44

Question 3

What is a mole?

Answer 3

A mole is a certain amount of atoms or molecules that is 6.02 x 10^23.

It happens to be Ar or Mr in grams
1 mole of any gas is 24dm^3 .

Think of it as a recipe amount. number in front of an ingredient.

Question 4

Moles equation?

Answer 4

Mass = Mr x moles

Question 5

percentage change?

Answer 5

(difference/original) x100

Question 6

what is yeild and working out percentage yield

Answer 6

yield= the amount you got from what you should get (basically efficiency)

To work out percentage yeild:

(actual mass got/theoretical yield) x100

Question 7

what is atom economy?

Answer 7

How many atoms of your reactant end up in your useful products

useful / total in

Question 8

reasons why percent yeild is less then 100% ?

Answer 8

• Not all the reactants react
• Some product is lost
• Some product will react with the original reaction

Question 9

What is a limiting reactant?

Answer 9

The reactant with the shortest supply that is used up in the reaction is the limiting reactant (because it limits the amount of product that is formed)

Question 10

How to work out the limiting reactant?

Answer 10

to work out you:

. write the equation

. write the Mr underneath

.Substitute one mass in and work out the scale factor

.apply the scale factor to the other reactant to work out how much should be used.

Question 11

Empirical formula?

Answer 11

1. write the symbols
2. write the mass
3. write the Ar
4. divide the massess by the Ar
5. Divide by the smallest number
6. write the formula

Question 12

Balancing equations using mass?

or moles

Answer 12

to work out you:

1- write down the symbol equation

2- write down the masses

3- write down the Mr (mass of 1 mole)

4- divide mass by Mr (calculating the number of moles)

5- Convert to the simplest ratio by dividing by the smallest number

6- write down the balanced equation

Question 13

What is concentration?

Answer 13

a measure of how many particles of solute are dissolved in a given volume of solution (usually dm ³)

Question 14

concentration equation?

Answer 14

mass of solute (g) / volume(dm ³)

ㅤmass
______
con x vol

Question 15

converting from cm3 to dm3?

Answer 15

to convert:

dm3 to cm3 = x 1000

cm3 to dm3 = /1000