I don't have baker's semi-sweet chocolate and recipe calls for a box with 8 squares. Can I replace with chocolate chips and if so what would be the ratio?
Yes, you can use the choco. chips. One square of chocolate is normally one ounce. Half a cup of chocolate chips is usually around three ounces. If you are looking to use 8 squares (8 ounces), you will need about 1 and a quarter cups of the chips (maybe just a tad more).
Some folks may come on and say that the chips are sweeter, less intense in flavour, etc., but when you are in a pinch, you can sub them out just fine. Doubtful you will notice any difference.
It depends. Check the ingredients on the chocolate chips. Some chocolate chips are really just chocolate (cocoa solids, cocoa butter, sugar, soy lecithin). If those are the only ingredients, you can substitute with no problems at all.
If there are other ingredients, such as vegetable oil, then you have to be more careful. You should still be able to make cookies and basic cakes, but more complex cakes may have issues and you can NEVER use that kind of chocolate for real candy making.