Label the hydrophilic and hydrophobic parts in the following compounds.
(a)`CH_3(CH_2)_10CH_2OSO_3^(-)Na^+` ,
(b)`CH_3(CH_2)_15-overset+N(CH_3)_3Br^-` ,
(c ) `CH_3(CH_2)_16COO(CH_2CH_2O)_n CH_2CH_2OH`

Explanation

To label the hydrophilic and hydrophobic parts of the given compounds, we will analyze each compound's structure step by step.

### Step 1: Analyze Compound (a) `CH_3(CH_2)_{10}CH_2OSO_3^{-}Na^{+}`

1. **Identify the structure**: This compound consists of a long hydrocarbon chain (`CH_3(CH_2)_{10}CH_2`) and a sulfate group (`OSO_3^{-}Na^{+}`).
2. **Hydrophilic part**: The sulfate group (`OSO_3^{-}Na^{+}`) is ionic and polar, making it hydrophilic.
3. **Hydrophobic part**: The long hydrocarbon chain (`CH_3(CH_2)_{10}CH_2`) is non-polar and hydrophobic.

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