5. A student spots an unknown sample on a TLC plate and develops it in ethanol. Only one spot appears, with an Rf of 0.97. Does this indicate that the unknown is a pure compound? What can be done to verify the purity of the sample?

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

How many moles are in 43.9 l of oxygen