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Which of the following statement(s) about 2-methyl-1-propanol, (CH3)2CHCH2OH, and...

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zorico91 | (Level 2) Honors

Posted September 11, 2012 at 9:09 PM via web

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Which of the following statement(s) about 2-methyl-1-propanol, (CH3)2CHCH2OH, and 1,3-propanediol, HOCH2CH2CH2OH are true?

Possible answers: 

A.) 2-Methyl-1-propanol is more soluble in water than is 1,3-propanediol because 2-methyl-1-propanol has a smaller molecular mass.

B.) 1,3-Propanediol is more soluble in water than is 2-methyl-1-propanol because 1,3-propanediol has a smaller molecular mass.

C.)2-Methyl-1-propanol is more soluble in water than is 1,3-propanediol because 2-methyl-1-propanol forms fewer hydrogen bonds with water.

D.) 1,3-Propanediol is more soluble in water than is 2-methyl-1-propanol because 1,3-propanediol can form multiple hydrogen bonds with water.

1 Answer | Add Yours

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jeew-m | College Teacher | (Level 1) Educator Emeritus

Posted September 12, 2012 at 8:22 AM (Answer #1)

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`(CH_3)_2CHCH_2OH` has one OH part which can bond with H of water.

`HOCH_2CH_2CH_2OH ` has two OH parts which can bond with H of water.

 

Molecular mass

`(CH_3)_2CHCH_2OH` = 74 g/mol

`HOCH_2CH_2CH_2OH` = 76 g/mol

 

Molecular mass of both substance are more or less the same. But `(CH_3)_2CHCH_2OH` has more carbon atoms which will cause a reduction of solubility in water.

The solubility of the substance depends on the type of bonds that it can make with water. If the bonding is powerful it will be highly soluble.

Both have H bonds with water. But `HOCH_2CH_2CH_2OH` has more H bonds than `(CH_3)_2CHCH_2OH`.

So `HOCH_2CH_2CH_2OH` will be more soluble in water than`(CH_3)_2CHCH_2OH`.


The correct statement is (D)

1,3-Propanediol is more soluble in water than is 2-methyl-1-propanol because 1,3-propanediol can form multiple hydrogen bonds with water.

 

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