For your celeron 847, I am not seeing the NM70 chipset, nor can I find the NM70 chipset.
This may be a specific OEM product. One of the Intel support engineers may have more information.
Thank you for posting in the Intel Community.
We don't have drivers available for Google Chrome OS on https://downloadcenter.intel.com/, to get the drivers for your system set up we recommend contacting the Original Equipment Manufacturer (OEM) in your case ACER® (https://www.acer.com/ac/en/US/content/support).
Hope this helps.
Intel Customer Support Technician
Under Contract to Intel Corporation