Consider the reaction. 4 k(s) + o2(g) s 2 k2o(s) the molar mass of k is 39.09 g> mol and that of o 32.00 g> mol. without doing any calculations, pick the condi- tions under which potassium is the limiting reactant and explain your reasoning. a. 170 g k, 31 g o2 b. 16 g k, 2.5 g o2 c. 165 kg k, 28 kg o2 d. 1.5 g k, 0.38 g o2

Answer : The correct option is (d) 1.5 g K, 0.38 g O₂

Explanation :

The molar masses of potassium and oxygen are very close to each other. Therefore we can assume them to be equal. If we assume that, then according to reaction stoichiometry, 4 moles of K are needed to react with 1 mol of O₂. Since the molar masses are assumed to be equal , we can say that the mass of potassium needed to react with that of oxygen should be 4 times the mass of oxygen.

From the given options, the only option that has less amount of K is option d.

Here, 0.38 g of oxygen needs 0.38 x 4 = 1.52 g of K. But the given mass of potassium is 1.5 g which is less. This indicates that potassium is the limiting reactant as we do not have enough potassium to completely react with all of the oxygen.

Therefore option d is the correct option

the answer is 75.0%.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.