Critical temperatures and densities of 24 n-alkanones with 10-14 carbon atoms have been measured. These alkanones were found to be thermally unstable at temperatures below their critical temperature, whereas in an earlier publication, it was reported that alkanones with fewer than 10 carbon atoms were thermally stable up to their critical temperatures. The data show smooth behavior of the critical temperatures and densities with carbon number for these substances. The critical temperatures of the isomeric n-alkanones increase with increasing carbon number, but the critical densities decrease as the carbon number increases. Both properties approach those of the corresponding n-alkane as the carbon number increases. In addition, the critical temperatures of the n-alkanones decrease as the carbonyl group is located further toward the center of the carbon chain, while the critical densities remain virtually constant. New correlations are reported for the critical temperature and density of members of the n-alkanone series.