Complete question:
Consider the hypothetical reaction 4A + 2B → C + 3D
Over an interval of 4.0 s the average rate of change of the concentration of B was measured to be -0.0760 M/s. What is the final concentration of A at the end of this same interval if its concentration was initially 1.600 M?
Answer:
the final concentration of A is 0.992 M.
Explanation:
Given;
time of reaction, t = 4.0 s
rate of change of the concentration of B = -0.0760 M/s
initial concentration of A = 1.600 M
⇒Determine the rate of change of the concentration of A.
From the given reaction: 4A + 2B → C + 3D
2 moles of B ---------------> 4 moles of A
-0.0760 M/s of B -----------> x

⇒Determine the change in concentration of A after 4s;
ΔA = -0.152 M/s x 4s
ΔA = -0.608 M
⇒ Determine the final concentration of A after 4s
A = A₀ + ΔA
A = 1.6 M + (-0.608 M)
A = 1.6 M - 0.608 M
A = 0.992 M
Therefore, the final concentration of A is 0.992 M.
I had the same question. I'm pretty sure it's 23 seconds. :)
Answer:
Magnesium is the correct answer
Explanation:
It is magnesium because as we move down the periodic table group, atomic sizes increase which is as a result of lesser forces of attraction between nucleus and valence of an atom which makes the atom to be prone to leave as electrons so easily, elements become more reactive.
But as we move along the period , atomic sizes decrease because there is a more force of attraction between nucleus of an atom and it valence electrons making it less reactive just as the case in magnesium. Other elements are more reactive than it across the group.