Low disk space in filesystem root

Since you are running Chrome, I infer you are running a Desktop version of Ubuntu and have an unpriv'd user you web browse, run applications, and sudo from for administrative purposes.

What I don't see is a separate user partition mounted on /home to keep user data from running the OS out of disk space. 24G is not all that much for a desktop environment. If the OS has to share it with users, you will eventually run your OS out of disk space - something you want to avoid. But to the immediate problem...

Let's be sure we know where the problem is. Please post the results of sudo du -sh /home. If this is a significant chunk of your 25G, then ...

Use sudo find /home -size +2G to locate big files in your user space. Keep reducing the size parameter and eliminating any files you can live without. If you are like most of us, you likely have a few downloaded ISOs lying around. If you are saving significant video or picture files - 25G will not go very far - you'll need another hard drive.

In the event that the /home space is NOT the culprit, you can scan the whole system from the top using sudo du -sk /* 2>/dev/null | sort -nk1. Find the top space eater and scan it's subfolders eliminating what you can as you go.

Good Luck, Nova