Page 2 OT Question 2 (1 point) Previously correct
Potassium chlorate decomposes into potassium chloride and oxygen gas according to
the following equation:
2 KCIO3 --> 2 KCI + 3 02
Use the equation above to answer the questions that follow:
How many moles of potassium chlorate will be needed to decompose to produce 8
moles of oxygen?
Do not put the answer in scientific notation. Do not include the substance as part of
your unit. Units should be all lowercase letters and singular (not plural) and no
spaces among units. You will choose from the following units:
8
g/mol
Son out

a. a clone will be physically identical to the original, but won’t be genetically identical

have a good day!

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years

"the periodic table is arranged in order of atomic number."