Insert widget between latest posts on mobile devices only

I have 2 columns. One column with latest 10 articles generated by Visual Composer, displayed 2 per row, and one column with widgets (banners).
Example:
| post1 post2 | banner |
| post3 post4 | banner |
| post5 post6 | banner |
How can I make each banner to show between rows, on mobile devices only?
Example:
| post1 post2 |
banner
| post3 post4 |
banner
| post5 post6 |
banner

Thank you!