One mole of 1-methoxy-4-(2-methoxyethoxy)benzene, $CH X_{3} O - C X_{6} H X_{4} - O - CH X_{2} CH X_{2} - O - CH X_{3}$ (para-disubstituted ring), is heated with a large excess of concentrated HI until every ether linkage is cleaved, and every alkyl-oxygen bond that can be cleaved is converted to an alkyl iodide. Each aryl alkyl ether consumes one mole of HI and each dialkyl ether consumes two moles of HI. How many moles of HI are consumed? Give your answer as an integer.

Numerical answer type, tolerance 0.5.

Answer: 4

The molecule contains three ether oxygens:

Ar - O - CH X_{3}

(aryl alkyl),

Ar - O - CH X_{2} X^{-}

(aryl alkyl) and

- CH X_{2} - O - CH X_{3}

(dialkyl). The two aryl alkyl ethers use

1 + 1 = 2

mol of HI to give the phenol and alkyl iodides. The dialkyl ether uses 2 mol of HI to give two alkyl iodides and water. The total is

2 + 2 = 4

mol.