# Chemistry help please? PLEASE explain your answers, thanks!?

Hi---Could someone please help me??? I am struggling! PLEASE explain your answers so I can follow you. Thanks to all. All help is greatly appreciated! :)

What is the empirical formula & empirical formula mass for each of the following compounds?

(a)C2H4

(b)C2H6O2

(c)N2O5

(d)Ba3(PO4)2

(e)Te4I16

### 3 Answers

- 1 decade agoFavorite Answer
Empirical formula is the simplest formula that represents the whole number ratio between the elements in a compound.

a) C2H4: Divide the subscripts by 2 to get the Empirical formula

Empirical formula is CH2

Empirical formula mass = 1(12.01 g/mol) + 2(1.008 g/mol) = 14.03 g/mol

b) C2H6O2 (divide the subscripts by 2)

Empirical formula is CH3O; Empirical formula mass = 1(12.01 g/mole) + 6(1.008 g/mole) + 1(16.0 g/mole) = 34.1 g/mole

c) N2O5 (There is no common factor for 2 and 5). So the empirical formula is N2O5 (the same as molecular formula)

Empirical Formula mass = 2 (14.0 g/mole) + 5(16.0 g/mole) = 108 g/mole

d) Empirical formula is Ba3(PO4)2 (Same as molecular formula)

Empirical formula mass = 3(137.33 g/mole) + 2(30.97 g/mole) + 8(16.0 g/mole) = 601.9 g/mole

e) Te4I16 (4 is the common factor for 4 and 16): Empirical formula = TeI4

Empirical formula mass = 1(127.60 g/mole) + 4(126.90 g/mole) = 635.2 g/mole

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- Dr WLv 71 decade ago
the empirical formula is the formula with the lowest whole # ratios of all the elements in the molecule.

(a). C2H4...

both 2 and 4 are divisible by 2. let's do that.. we get 2/2 =1... 4/2 =2... ie..CH2.. that is the empirical formula for C2H4. empirical formula mass = 12.01 + 2x1.008 = 14.03 g / unit

(b) C2H6O2.. divide all by 2.. CH3O is the empirical formula. mass = 12.01 + 3x1.008+ 16 = 31.0 g/unit

(c)N2O5.. cannot be divided into smaller whole numbers. mass = 108 g / unit

(d) Ba3(PO4)2. again, cannot be divided into smaller whole number ratios. mass = 602 g/unit

(e) Te4I16.. 4 and 16 can be divided by 4. TeI4 is the empirical formula. mass = 127.6+4*126.9 = 635 g/unit

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- 1 decade ago
a. This compound's name is ethene and mass compound 26

b. ethanediol 62

c. 110

d. .........

e.........

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