Radio active decay reactions follow first order rate kinetics.
a) The half life and decay constant for radio active decay reactions are related by the equation:



Where k is the decay constant
b) Finding out the decay constant for the decay of C-14 isotope:



c) Finding the age of the sample :
35 % of the radiocarbon is present currently.
The first order rate equation is,
![[A] = [A_{0}]e^{-kt}](https://tex.z-dn.net/?f=%20%5BA%5D%20%3D%20%5BA_%7B0%7D%5De%5E%7B-kt%7D%20%20%20)
![\frac{[A]}{[A_{0}]} = e^{-kt}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%5BA%5D%7D%7B%5BA_%7B0%7D%5D%7D%20%3D%20e%5E%7B-kt%7D%20%20)


t = 7923 years
Therefore, age of the sample is 7923 years.
What's wrong with this setup is the substrate on which you have positioned
the drop is "dirty and unclean" meaning it is not being dampened by
the solution. This action can be corrected by comprehensively cleaning the
substrate where the drop will be positioned.
Answer:
= 97.44 Liters at S.T.P
Explanation:
The reaction between Iron (iii) oxide and Carbon monoxide is given by the equation;
Fe2O3(s)+ 3CO(g) → 3CO2(g) + 2Fe(s)
From the reaction when the reactants react, 2 moles of Fe and 3 moles of CO2 are produced.
Therefore; Mole ratio of Iron : Carbon dioxide is 2:3
Thus; Moles of Carbon dioxide = (2.9/2)×3
= 4.35 moles
But; 1 mole of CO2 at s.t.p occupies 22.4 liters
Therefore;
Mass of CO2 = 22.4 × 4.35 Moles
= 97.44 L
Answer:
The process of elemental stratification relies on the diffusion velocity, which causes the migration of the different chemical elements within stars.
Explanation:
The molar mass is usually referred to with
M
, while the mass is referred to as
m
. The amount of substance is
n
. This gives you the following relationship:
=
M
=
m
n
Since you have given (C3H8)=11 g
m
(
C
3
H
8
)
=
11
g
and you already looked up (C3H8)=44.1 gmol−1
M
(
C
3
H
8
)
=
44.1
g
m
o
l
−
1
, you can use this formula to determine (C3H8)
n
(
C
3
H
8
)
.
In this question it is quite hard to explain the use of significant figures. Those are used to imply a certain inaccuracy. Not enough information is given by the question, as of how accurate the measurement is. It is a mere exercise of converting one property into another. Here you should not worry about it.