Chemistry Video 4

Question 1

Synthesis reaction

Answer 1

Two things become one thing. A + B -> AB

Question 2

Decomposition reaction

Answer 2

One thing becomes two things, energy must be supplied to break a bond (ex. heat as energy, sunlight as energy, or spontaneous). AB -> A + B

Question 3

Single displacement reaction

Answer 3

One compound swaps out one of its components with something else. Often REDOX reactions. AB + C -> AC + B

Question 4

Double displacement reaction

Answer 4

Two compounds each have 2 components and swap halves. Often precipitation reactions. AB + CD -> AD + CB

Question 5

Combustion reaction

Answer 5

Always has O2 as reactant and CO2 and H2O as the 2 products

Question 6

Conservation of mass

Answer 6

In a reaction, atoms are not created nor destroyed, they simply rearrange

Question 7

Electrolysis of water

Answer 7

Reactant is H2O, products are O2 gas and H2 gas

Question 8

Stoichiometry

Answer 8

Molecules react in certain numerical ratios

Question 9

Avogadro’s number

Answer 9

Number of items (ex. atoms, molecules) per 1 mole, 6.022*10^(23)

Question 10

One mole

Answer 10

The number of carbon atoms in 12 grams of carbon

Question 11

Percent composition

Answer 11

Percent of the molecular mass that is represented by each element in a compound.