Based on the given molecular formula C5H10O2 and the 1H-NMR spectrum data, we can deduce the structure of the unknown compound as follows:1. The molecular formula C5H10O2 suggests the presence of an ester or a carboxylic acid with an additional oxygen-containing functional group e.g., an ether or an alcohol .2. The presence of a singlet at 1.1 ppm indicates a methyl group CH3 that is not adjacent to any other protons.3. The singlet at 2.3 ppm suggests a methylene group CH2 that is not adjacent to any other protons.4. The singlet at 3.7 ppm indicates a methine group CH that is not adjacent to any other protons but is likely connected to an electronegative atom e.g., oxygen .5. The doublet at 2.9 ppm suggests a methylene group CH2 that is adjacent to another proton.Taking all this information into account, the most likely structure for the unknown compound is an ester with an ether group:CH3-O-CH2-CH2-C =O -O-CH3This structure is consistent with the given 1H-NMR data and the molecular formula C5H10O2.