If 19.3 moles of heptane (C7H16) are reacted with an excess of oxygen gas, how many moles of carbon dioxide (CO2) should be produced? (Round to the tenths place)

1 C7H16 + 11 O2 -> 7 CO2 + 8 H2O

Qand k are only the same when the forward rate of the reaction has reached zero.

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.