The Stereochemistry of an Sn1 Reaction

Departure of the leaving group (assisted by hydrogen bonding with solvent) leads to the carbocation. 

The carbocation is an achiral intermediate. Because both faces of the carbocation are the same, the nucleophile can bond with either face to form a mixture of stereoisomers. 

Additional solvent molecules (water) The product is a racemic mixture, deprotonate the alkyloxonium ion. 

The S m1 reaction of (S)-3-bromo-3-methylhexane proceeds with racemization because the intermediate carbocation is achiral and attack by the nucleophile can occur from either side. 

Keeping in mind that carbocations have a trigonal planar structure, (a) write a structure for the carbocation intermediate and (b) write structures for the alcohol (or alcohols) that you would expect from the following reaction  

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