Which of the following has a low HLB value?

The correct choice is mineral oil, which has a low HLB (Hydrophilic-Lipophilic Balance) value. HLB is a scale that measures the balance between the hydrophilic (water-attracting) and lipophilic (oil-attracting) properties of a surfactant or substance. A low HLB value typically indicates that a substance is more lipophilic and less hydrophilic.

Mineral oil, being a non-polar substance and primarily hydrophobic, aligns with this definition as it has little to no affinity for water, thus resulting in a low HLB value. This characteristic makes mineral oil effective for applications such as skin conditioning and barrier formation rather than emulsifying or solubilizing water-based formulations.

In contrast, substances like acids and alcohols usually have higher HLB values due to their polar groups, making them more hydrophilic. Hydrophilic substances, by definition, have a higher affinity for water, which is opposite to the low HLB value characteristic. Therefore, mineral oil stands out as the only choice with a low HLB value among the options provided.