Chapter 3

Question 1

What is a combination reaction?

Answer 1

two or more substances react to form one product

Question 2

What is a combination reaction between?

Answer 2

a metal and a nonmetal

Question 3

What is a decomposition reaction?

Answer 3

one substance undergoes a reaction to produce two or more other substances

Question 4

What is a combustion reaction?

Answer 4

proceeds with evolution of heat usually alos a flame reaction with oxygen in the burning of a match

Question 5

What are the products of a combustion reaction?

Answer 5

CO2, H2O

Question 6

What is the formula weight?(FW)

Answer 6

the sum of atomic weights of the atoms in the chemical formula of the substance

Question 7

What is the atomic weights? (AW)

Answer 7

atomic weights are on the period table

Question 8

What is percentage composition?

Answer 8

the percentage by mass contributed by each element in the substance

Question 9

How to find %mass composition of element?

Answer 9

(number of atoms of element)(atomic weight of element)/Formula weight of substance x 100

Question 10

What is avogadro’s number?

Answer 10

6.022 x 10^23

Question 11

how to find number of atom from g?

Answer 11

take the g and convert it to moles then multiply by 6.022 x 10^23

Question 12

What is molar mass?

Answer 12

Molar mass is the same as the atomic weight but in g

Question 13

What is the units of molar mass?

Answer 13

g/mol

Question 14

How to find mol of a element in a compound when given the percent of the element by mass in the compound.

Answer 14

change percent to g by removing the % if it is in a 100g sample then times it by the molar mass

Question 15

How to find mole ratio?

Answer 15

divide the larger number of moles by the smaller number to obtain the ratio

Question 16

After obtaining the mole ratio how do you find the emphirical formula?

Answer 16

find the closest number to the ratio whole number and then that equals number of each element in the compound

Question 17

How do you find the whole number multiple?

Answer 17

molecular weight/empirical formula weight

Question 18

How to find the mass of an element in the original sample when given the mass of the product?

Answer 18

Mass of produced x molar mass x moles produced x number of elements in molecule x moles of element in original sample x molar mass of element

Question 19

How to find reactans consumed or products formed in a reaction?

Answer 19

g of substance A x molar mass of A x moles of A x coeffecitans from equation x moles of B x molar mass of B = g of B

Question 20

What is a limiting reactant?

Answer 20

the reactant that is completely consumed in a reaction

Question 21

What are excess reactants?

Answer 21

any other reactants have leftover

Question 22

How to find limiting and excess reactants?

Answer 22

USE a BCA table

Question 23

How to make a BCA table?

Answer 23

Before reaction: (products will =0)
Change(eaction
After reaction:(limiting will = 00

Question 24

what is theoretical yield?

Answer 24

The quantity of product calculated to form when the limiting reactant is fully consumed

Question 25

what is the actual yield?

Answer 25

the amount of product actaully obtained

Question 26

How to find percent yield?

Answer 26

actual yield/ theoretical yield x 100