What is the percent of O in
CO2?
(C = 12.01 amu, O = 16.00 amu)

One mole of atoms of oxygen has a mass of 16 g, as 16 is the atomic weight of oxygen, and contains 6.02 X 1023 atoms of oxygen.

hope its helps thanks my this answer.

            12.33 cal/sec

Explanation:

As we know,

                          1 Kcal  =  1000 cal

So,

                     0.74 Kcal  =  X cal

Solving for X,

                      X =  (0.74 Kcal × 1000 cal) ÷ 1 Kcal

                      X =  740 cal

Also we know that,

                      1 Minute  =  60 Seconds

Therefore, in order to derive cal/sec unit replace 0.74 Kcal by 740 cal and 1 min by 60 sec in given unit as,

                                       = 740 cal / 60 sec

                                       = 12.33 cal/sec