Zach needs to make a 2.75 m solution of naoh(molar mass=40.00g/mol) using 350. g of water. what mass of naoh should he dissolve in the water to make this solution? show the steps

Awhite powder is added to a solution. the images show observations made before the powder is added, just after the powder has been added, and a little while later. (the liquid in the small beaker is phenol red solution.) what evidence shows that a chemical change has taken place?