Answer:
Units for parameter k would be [tex]minutes^{-1}[/tex].
Step-by-step explanation:
The concentration of CA0 is given in M (moles per liter), which is the unit for CA; if we show units inside parenthesis in the equation, it would be:
[tex]CA (M)=CA0 (M) *(1-e-k(?)*t(minutes))[/tex]
For the concentration units of CA0 not to be affected by the units of the factor (1-e-k*t), this factor would have to be a number without units.
Since 1 is a constant without units, for the constant e to be able to subtract from 1 it would have to be a number without units, which also applies to the factor k*t.
For the factor k*t to be a number without units, k must have units that can be canceled when multiplied by t, which is given in minutes, so k must have units of [tex]\frac{1}{minutes} =minutes^{-1}[/tex]
This can be confirmed by operating the equation using only its units (units of parameter k are noted by a question mark):
[tex]M=M(0-0-?*minutes)[/tex]
[tex]\frac{M}{M} =?*minutes[/tex]
[tex]1=?*minutes[/tex]
[tex]\frac{1}{minutes}=?[/tex]
[tex]minutes^{-1}=?[/tex]
