Gen & Analytical Chemistry #2

Question 1

electrons transfer from one element to another

Answer 1

oxidation state

Question 2

what is the oxidation number of oxide, peroxide and superoxide?

Answer 2

oxide: -2
peroxide: -1
superoxide: -1/2

Question 3

what happens to the oxidation number if H2O is given?

Answer 3

H2 becomes + since O is -

metal is always positive while non-metal always negative

Question 4

are single replacement redox reactions?

Answer 4

yes

Question 5

if all are compound in the reaction, is it still considered as redox reaction?

Answer 5

no since there has to be a pure substance

Question 6

T/F: are combustion reactions always redox reactions?

Answer 6

yes

Question 7

are double replacement reactions such as precipitation and acid base reactions considered as redox rxns?

Answer 7

no because they are all made up of compounds

Question 8

oxidation state of any pure element like H, O2, or simply Zn?

Answer 8

0

Question 9

hydrogen when bonded to a nonmetal has an oxidation state of ______

Answer 9

+1

Question 10

hydrogen bonded with a metal

Answer 10

-1 since it is more electronegative than most metals

Question 11

oxidation states can be related to electronegativity of elements

state an atom and its electronegativity value

Answer 11

H - 2.1

B 2.0
C 2.5
N 3.0   P 2.1
O 3.5   S 2.5
F  4.0    Cl 3.0     Br 2.8    I 2.5

Question 12

amount of products formed when limiting reactant is fully consumed

Answer 12

theoretical yield

Question 13

amount of products obtained which is said to be lower than theoretical yield

Answer 13

actual yield

Question 14

formula for percent yield

Answer 14

actual/theoretical x 100

If more than 100, it means that there might be a mistake in calculations

Question 15

the reactant responsible for limiting the amount of products formed in the reaction

Answer 15

limiting reactant/reagent

Question 16

how to get leftover from excess reactant? state the formula/procedure

Answer 16

to get the amount of excess reactant used, multiply the limiting reactant in moles to the moles of the excess reactant

after doing so, minus the amount of excess reactant to the amount of used excess reactant by the limiting reactant

convert to grams if asked

Question 17

where the bonds between atoms are assumed to be ionic

Answer 17

oxidation state

Question 18

electron is transferred from one species to another

Answer 18

redox reaction

Question 19

what is half-reaction

Answer 19

this is when the equation is divided into oxidation and reduction

Question 20

redox reaction is where mass and charges are

Answer 20

balanced together