So my chem final is tonight in like 7 hours, and I'm looking over this practice test that I've heard is very similar to last years final, few problems I don't understand how to do so hopefully you guys/girls can help, and ill forever be in your debt  
  
Problem 1: 
 
Problem 2: On this problem I assume the orbital B is the largest since principal quantum number = Size 
 
Problem 3: 
 
Problem 4/5: For question 27, it appears like a trigonal pyramid so the angle should be 120 degrees ? And on Problem 28, the carbon is surrounded by 4 electron domains so it would be a tetrahederal which means its sp3 hybridized orbitals ? 
 
Problem 6/7: Problem 33 always trips me up I forget how to calculate percent yield of  a substance  and for Problem 34 do I have to find the molar mass of the solute NaNo3 ?  
 
  
Thanks !!!!!!