To determine which order of the reaction it is, first we need to calculate the rate of change of moles.
the data is as follows
time 0 40 80 120 160
moles 0.100 0.067 0.045 0.030 0.020
Q1)
for the first 40 s change of moles ;
= -d[A] / t
= - (0.067-0.100)/40s
= 8.25 x 10⁻⁴ mol/s
for the next 40 s
= -(0.045-0.067)/40
= 5.5 x 10⁻⁴ mol/s
the 40 s after that
= -(0.030-0.045)/40 s
= 3.75 x 10⁻⁴ mol/s
k - rate constant
and A is the only reactant that affects the rate of the reaction
rate = k [A]ᵇ
8.25 × 10⁻⁴ mol/s = k [0.100 mol]ᵇ ----1
5.5 x 10⁻⁴ mol/s = k [0.067 mol]ᵇ -----2
divide the 2nd equation by the 1st equation
1.5 = [1.49]ᵇ
b is almost equal to 1
Therefore this is a first order reaction
Q2)
to find out the rate constant(k), we have to first state the equation for a first order reaction.
rate = k[A]ᵇ
As A is the only reactant thats considered for the rate equation.
Since this is a first order reaction,
b = 1
therefore the reaction is
rate = k[A]
substituting the values,
8.25 x 10⁻⁴ mol/s = k [0.100 mol]
k = 8.25 x 10⁻⁴ mol/s /0.100mol
= 8.25 x 10⁻³ s⁻¹
C) Tc-99 is a radioactive isotope also known as radioisoptope.
A. experiment 1 i believe its the best answer
When earth turns once it's a day
The question is incomplete, the complete question is;
the element vanadium is a solid at room temperature, and its density is 6110 kilograms per meter cubed. its melting point is 1910 degrees celsius.” which correctly evaluates the statement? not reliable because opinions are presented, reliable because testable facts are presented, not reliable because it is very brief ,reliable because metric units are used
Answer:
reliable because testable facts are presented
Explanation:
Science is a body of knowledge that deals with testable facts. Science is highly empirical and any superstitious proposition is quickly discarded as nonsense.
The statement, ''The element vanadium is a solid at room temperature, and its density is 6110 kilograms per meter cubed. Its melting point is 1910 degrees Celsius" presents facts that can be verified by laboratory investigation.
Hence we can conclude that the given statement is reliable because it contains testable facts.
