§21.101. tert-Butyl alcohol.

Acidity (as acetic acid). 0.003 percent by weight maximum.

Color. Colorless.

Distillation range. When 100 mL of tertiary butyl alcohol are distilled, none should distill below 78 °C. and none above 85 °C. More than 95 percent should distill between 81 °−83 °C.

Dryness at 20 °C. Miscible without turbidity with 19 volumes of 60° Bé1. gasoline.

Freezing point (first needle). Above 20 °C.

Identification test. Place five drops of a solution containing approximately 0.1 percent tertiary butyl alcohol in ethyl alcohol in a test tube. Add 2 mL of Denige's reagent (dissolve 5 grams of red mercuric oxide in 20 mL of concentrated sulfuric acid; add this solution to 80 mL of distilled water, and filter when cool). Heat the mixture just to the boiling point and remove from the flame. A yellow precipitate forms within a few seconds.

Nonvolatile matter. Less than 0.005 percent by weight.

Odor. Characteristic odor.

Residual odor after evaporation. None.

Specific gravity at 25 °/25 °C. 0.780 to 0.786.