If the initial [NO2] is 0.260 M, it will take s for the concentration to drop to 0.150 M. If the initial is 0.260 , it will take for the concentration to drop to 0.150 . 1.01 5.19 0.299 0.0880 3.34

The question is incomplete, here is the complete question:

At elevated temperature, nitrogen dioxide decomposes to nitrogen oxide and oxygen gas

The reaction is second order for with a rate constant of at 300°C. If the initial [NO₂] is 0.260 M, it will take ________ s for the concentration to drop to 0.150 M

a) 1.01    b) 5.19     c) 0.299      d) 0.0880     e) 3.34

The time taken is 5.19 seconds

Explanation:

The integrated rate law equation for second order reaction follows:

where,

k = rate constant =

t = time taken  = ?

[A] = concentration of substance after time 't' = 0.150 M

= Initial concentration = 0.260 M

Putting values in above equation, we get:

Hence, the time taken is 5.19 seconds

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.