Miriatic acid will do the trick. Find it at any pool supply store (about $2.00 a gallon). USING HEAVY RUBBER GLOVES, mix it about 50/50 with water and mop or sponge the entire affected area.

....for more stubborn areas it can be used straight.

For cleaning off tools you need to use a mild acid found products such speedy or super dissolver

http://www.concrete-dissolver.com

Muriatic is dangerous and much too strong for most clean up applications