plz plz help. its public economics

1. In the standard trade model from class where capital is mobile but labor is immobile, is a tax to capital income whose proceeds are given to workers necessarily welfare enhancing to workers? Why? {10 pts.) 2. In a setup where a distorting tax to wage income produces the tax revenues schedule to display a Laffer curve pattern, why is that for some range of the tax rate revenues increase and afterwards fall? {10 pts.)