Question

a substance with a reported melting point of 134 - 136 °c melts at 128 - 132 °c in your experiment. what does this suggest? the sample has sublimed the sample is pure the sample contains impurities the thermometer is malfunctioning

Explanation:

Impurities lower and broaden melting - point range. The experimental range is lower than reported, suggesting impurities.

Answer:

The sample contains impurities