PLEASE HELP How would you modify the flashlight to increase the amount of energy it releases

Which of these reactions are redox reactions? check all that apply. cd + hcl → cdcl2  + h2cucl2  + na2s → 2nacl + cuscaco3  → cao + co2          2zns + 3o2  → 2zno + 2so2          ch4  + 2o2  → co2  + 2h2o

2-bromo-2-methylbutane undergoes an e1 elimination reaction in the presence of ethanol. in the next reaction only one of the possible products is represented. although the product shown is not the major product of the reaction, notice that there is more than one way it can be produced. complete the mechanism and draw the missing substances.

1.17 mol hcl and 2.5 mol naoh react according to the equation hcl + naoh -> nacl + h2o . if the limiting reactant is hcl, determine the amount of excess reactant that remains. answer in units of mol.