Acid-Base Indicators

Acid-Base Indicators Wexler Films Man in white lab coat working in laboratory. Two beakers of ordinary tea, lemon juice changes their color; as does vinegar in red cabbage. Showing changing colors on litmus paper by adding to litmus. Bromthymol Blue added to pure distilled water (neutral). Hydrogen chloride gas added to water (acidic). Solid sodium hydroxide added to another beeker (for basic solution). 18:40:32 Bromthymol Blue added: yellow in acidic, intermediate in neutral water & blue in basic solution. By evaporation other colors result (red in acidic). Explains why color changes. All indicators can accept & donate protons thereby giving color changes. Animation & Animated diagram showing process. 18:45:53 Two hands move petrie dishes. 18:47:22 Hand writes chemical equation. Talks of ionization constants. 18:49:06 Methyl-orange added. Equation written below petrie dishes. 18:51:30 Methyl-red added to petrie dishes & colors changed w/ ionization rate explained. Equation written. Others done. 18:55:02 Arm of technician & adding to beaker of water. Burrettes, beakers and stirring mixer for good visual swirl. Oddities; Science; Scientists; Gags; Chemical laboratory; Slow speaking; 1962; Educational Film; NOTE: Any one continuous minute sold at per reel rate.