How Does Potassium Chloride Increase The Temperature Of Ice Faster Than Saltss

My hypothesis stated that I believed salts with a larger density will increase the temperature of the ice faster than salts with a smaller density because the heavier salts will sink through the ice faster since they have a heavier density than water and stop the molecules from staying ice faster, consequently raising the temperature of the solution, than lower density salts would. . The data I collected shows potassium chloride, which has a density of 1.98 g/㎤, increased the solution’s temperature at a faster rate than any of the other solutions. Using the data I collected, I can unequivocally state that my data did not support my hypothesis. Potassium chloride had the fifth highest density out of the seven salts I used in my experiment. The highest density salt I used, sodium carbonate, had no change in temperature. I do not think there were any outliers in my data because none of the temperatures of the salts went beyond a range of 6°C.
One possible source of error could have occurred because the solutions did not reach a thermal equilibrium with the freezer. This could result in the salt solutions starting off at varying temperatures. Starting at varying temperatures could result in certain salt solutions melting at rates they would not melt at if all the solutions started at the same temperature. A possible way to fix this error would be to leave all the solutions in the freezer until they reached a thermal equilibrium with the freezer. This means that I would take the solutions out of the freezer when they reached -80°C, the temperature of the freezer the solutions were placed