Answer:
Enriched uranium-
Explanation:
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written ²³⁵U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (²³⁸U with 99.2739–99.2752% natural abundance), uranium-235 (²³⁵U, 0.7198–0.7202%), and uranium-234 (²³⁴U, 0.0050–0.0059%). U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons.
I think that it is qualitative data
Answer:
b) The dehydrated sample absorbed moisture after heating
Explanation:
a) Strong initial heating caused some of the hydrate sample to splatter out.
This will result in a higher percent of water than the real one, because you assume in the calculation that the splattered sample was only water (which in not true).
b) The dehydrated sample absorbed moisture after heating.
Usually inorganic salts may absorbed moisture from the atmosphere so this will explain the 13% difference between calculated water percent the real content of water in the hydrate.
c) The amount of the hydrate sample used was too small.
It will create some errors but they do not create a difference of 13% difference as stated in the problem.
d) The crucible was not heated to constant mass before use.
Here the error is small.
e) Excess heating caused the dehydrated sample to decompose.
Usually the inorganic compounds are stable in the temperature range of this kind of experiments. If you have an organic compound which retain water molecules you may decompose the sample forming volatile compounds which will leave crucible so the error will be quite high.
Answer:
Rate constant = 0.0237 M-1 s-1, Order = Second order
Explanation:
In this problem, it can be observed that as the concentration decreases, the half life increases. This means the concentration of the reactant is inversely proportional to the half life.
The order of reaction that exhibit this relationship is the second order of reaction.
In the second order of reaction, the relationship between rate constant and half life is given as;
t1/2 = 1 / k[A]o
Where;
k = rate constant
[A]o = Initial concentration
k = 1 / t1/2 [A]
Uisng the following values;
k = ?
t1/2 = 113
[A]o = 0.372M
k = 1 / (113)(0.372)
k = 1 / 42.036 = 0.0237 M-1 s-1
