The ether shown is heated with excess concentrated $HI$ until every cleavable carbon-oxygen bond is broken. Assume that each bond from oxygen to an sp3 carbon consumes one $HI$ (converting that carbon to $C - I$ ) and that the oxygen-aryl bond is never cleaved. How many moles of $HI$ are consumed per mole of ether? Answer as an integer.

Numerical answer type, tolerance 0.5.

Answer: 3

The ether is 1-methoxy-2-phenoxyethane. It has three oxygen-to-sp3-carbon bonds:

CH X_{3} - O

, the

O - CH X_{2}

bond at the methoxy end and the

CH X_{2} - O

bond at the phenoxy end. The aryl-oxygen bond does not cleave. The products are

CH X_{3} I

ICH X_{2} CH X_{2} I

and phenol, so 3 mol of

HI

are consumed.