I need help with chem again!

<p>Can someone explain the following?</p>

<p>1) why are both reactions spontaneous?
I. Cl2 + 2Br= Br2 + 2Cl
II. Br2+ 2I = I2 + 2Br</p>

<p>2) Why are the carbon-carbon-carbon bond angles in CH3CHCH2 closest to 120 degrees?</p>