Substances

Question 0

What is the % of hydrogen in water?

H2O
H=1
O=16

Answer 0

1 + 16 + 16 = 33
1 divided by 33 = 0.0303
0.03 x 100 = 3.

Question 1

How to work out the % of an element present in a substance?

Answer 1

The relative atomic mass of the wanted element divided by the total mass of all elements in the substance.

Question 2

What is yield?

Answer 2

Yield is the amount of product created.

Question 3

How can yield be lost?

Answer 3

Spillage, evaporation or human error.

Question 4

How do you work out yield?

Answer 4

You divide what you actually made by what you should have made.

Question 5

What is a mole?

Answer 5

How many atoms in a substance

Question 6

What is the formula for moles?

Answer 6

Moles = mass divided by Mr

Question 7

How do you figure out a mole of an element?

Answer 7

Multiply the percentage of the element by the relative atomic mass

Question 8

If a compound contains 75% carbon and 25% hydrogen what is one mole of carbon?

Answer 8

Carbon = 12

75 divided by 12 = 6.25 (one mole)