Please someone help me

Given the table below, what is the chemical formula for a compound between rb and the nitrate ion no3 -1? nitrate ion no3 -1 phosphate po4 -3 sulfate so4 -2 acetate c2h3o2 -1 ammonium nh4 +1 chromate cro4 -2 carbonate co3 -2 dichromate cr2o7 -2 permanganate mno4 -1 sulfite so3 -2 rbno3 rb2no3 rb(no3)2 rb2(no3)3

In a heat engine of 1000 j of heat enters the system and the piston does 500 j of work what is the final internal energy of the system if the inital energy was 2000 j we have to do all of these down here 1)write the equation 2)list out your know variables 3)plug the numbers into the equations 4)solve 5)write your solution statemtn that includes inital energuy and final energuy added

The data below were determined for the reaction shown below. s2o82– + 3i – (aq) → 2so42– + i3– expt. # [s2o82–] (m) [i –] (m) initial rate 1 0.038 0.060 1.4 × 10 – 5 m/s 2 0.076 0.060 2.8 × 10 – 5 m/s 3 0.076 0.030 1.4 × 10 – 5 m/s the rate law for this reaction must be: