Will iPhone 11 charge properly using a MagSafe charger?

Yes, you can use a MagSafe charger on an iPhone 11. It is a QI wireless charger. That said, MagSafe really is specifically designed for iPhone 12 and 13 phones. There are magnets built into them to ensure the charger attaches exactly where the charging coil is located on the back of the phone.

Given MagSafe chargers cost more than traditional QI chargers, I'm not sure why you'd buy one for an iPhone 11, unless you have an iPhone 12 or 13 in the house along with an iPhone 11 and you just want to make sure the charger will work with an 11. And it will.

Ps: I see you asked in another thread you started. I personally wouldn't add a magnet to the back of an iPhone 11, which wasn't designed for MagSafe.