C2h4 + O2 - CO2 + H2O
If we start with 20 grams of CH4, how many moles of CO2 will form?

1.428mol of CO2

Explanation:

C2H4 + 3O2 —> 2CO2 + 2H2O

First let us calculate the number of mole present in 20g of C2H4. This is illustrated below:

Molar Mass of C2H4 = (12x2) +(1x4) = 24 + 4 = 28g/mol

Mass of C2H4 = 20g

Number of mole of C2H4 = Mass /Molar Mass

Number of mole of C2H4 = 20/28 = 0.714mol

From the balanced equation,

1mole of C2H4 produced 2moles of CO2.

Therefore, 0.714mol of C2H4 will produce = 0.714 x 2 = 1.428mol of CO2

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.