An alcohol is 68.84 % c and 4.962 % h by mass. the rest is oxygen. what is the empirical formula of the alcohol? enter the elements in the order c, h, and then o.

The empirical formula is C₇H₆O₂.

Assume that you have 100 g of the compound.

Then you have 68.84 g C and 4.962 g H.

Mass of O = (100 – 68.84 – 4.962) g = 26.20 g O.

Now, we must convert these masses to moles and find their ratios.

From here on, I like to summarize the calculations in a table.

Element     Mass/g    Moles    Ratio     ×2   Integers  

     C           68.84      5.732    3.501  7.001       7

     H            4.962    4.923    3.006  6.012      6

     O          26.20      1.638     1          2             2

The empirical formula is C₇H₆O₂.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

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.