Quantitative Chemistry basics

Which of these is NOT true?

• · In a chemical reaction, no atoms are lost or made, they are only re-arranged

• · The mass of reactants = mass of products

• · Atoms can be created or destroyed

• · Atoms cannot be created or destroyed

If the sum of the reactants Mr’s is 52, what is the sum of the products Mr’s?

• 26

• 52

• 104

• It's impossible to tell

When weighed, the sum of the mass of the reactants is 80g, the sum of the mass of the products is 78g. Why?

• · An error has been made measuring

• · One of the products is a gas

• · One of the reactants is a gas

• · One of the products is an oxide

Why does the mass in some chemical reactions seem to increase?

• · An error has been made measuring

• · One of the products is a gas

• · One of the reactants is a gas

• · One of the products is an oxide

Which is the correct representation of the formula of water?

• · H²O

• · H₂O

• · h₂O

• · O₂H

What is the relative atomic mass of Carbon?

• 6

• 12

What is the relative atomic mass of Magnesium?

• 24

• 12

What is the relative atomic mass of Chlorine?

• 17

• 35

• 35.5

• 36

M_r represents what?

• · Relative atomic mass

• · Relative formula mass

What is the relative formula mass of Carbon dioxide, CO₂?

• 22

• 28

• 38

• 44