The analysis of 2.12 of a compound gave 0.33 of carbon, 1.82 of the same compound gave 1.53 of sulphur. Calculate the emperical formula

CS₂

Explanation:

To find the empirical formula we need to determine first the percentage of each atom in the molecule. Then, we need to find the moles and, as empirical formula is the simplest whole-number ratio of atoms we can solve the empirical formula:

%C:

0.33gC / 2.12g * 100 = 15.6%

%S:

1.53g S / 1.82g * 100 = 84.1%

In a basis of 100, the moles of each atom are:

C:

15.6g C * (1mol / 12.01g) = 1.30 moles

S:

84.1g S * (1mol / 32.065g) = 2.62 moles

The ratio of Sulphur-Carbon is:

2.62mol / 1.30mol = 2

That means empirical formula is:

the dependant variable is spilled water

the independent is the heat

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.