Add new column to dataframe but the order is changed in pandas

Question

I am using the below code to add another column (label), but I don't understand why the order does not follow what I expected. It should start from 'meanMWac', 'meanMWin'..'SDNumHAcceptorsin'. What part do I miss in the code to make it rearrange in the order that I want above mentioned?

label={'meanMWac', 'meanMWin','SDMWac', 'SDMWin',
     'meanLogPac', 'meanLogPin','SDLogPac','SDLogPin',
     'meanNumHDonorsac','meanNumHDonorsin','SDNumHDonorsac','SDNumHDonorsin',
    'meanNumHAcceptorsac', 'meanNumHAcceptorsin','SDNumHAcceptorsac','SDNumHAcceptorsin'}

statistic_Ro5 = pd.concat(total, axis=0)
Ro5 = pd.DataFrame(statistic_Ro5, columns=["stat"])
Ro5['label']= label
Ro5