Answer:
Correct option is
A
Explanation:
The number of molecules of CO involves in the slowest step will be 0 because CO is not involve in the slowest step i.e. rate determing step.
Because displacement of water is the convenient way to obtain gas.
6.9 x 10^-4 would be .00069 written in scientific notation

Here we go ~
1 mole of
has 6.022 × 10²³ molecules of the given compound.
So, 0.78 mole of
will have ~


The answer to this is 22, confirmed by gradpoint