Sodium Hydroxide in Water

When sodium hydroxide is dissolved in water it feels warm, which indicates an exothermic reaction.
NaOH (s) → Na+ (aq) + OH- (aq)
- Dissolution / Exothermic Reactions / Lesson Plans / Solubility
- 1.3b / 5.4e / 6.5a / CH.2h / CH.3e / CH.5g / PS.5b
M&M Color Wheel

When M&M’s are placed in water, the outer shell, which is made of sugar, dissolves. The sugar moves from a place of high concentration (the M&M) to a place of low concentration (the water away from the M&M). When the sugar shell dissolves and moves outward, it takes the layer of food dye with it. When more than one M&M is placed into a petri dish the colors do not mix because the concentration of sugar at the interface is approximately the same. Also, around the bottom of the M&M water appears cloudy because the sugar that is dissolved is more dense than the water, so it sinks.
- Density / Diffusion / Dissolution / Mixtures / Physical Change / Solubility / Uses Household Items
- 1.3b / 3.3a / 3.3c / 5.4e / 6.5a / BIO.2a / BIO.3d / CH.2h / CH.5g / ES.10a / PS.2b / PS.2d / PS.5a
Ammonium Nitrate in Water

When ammonium nitrate is dissolved in water it feels cold, which indicates an endothermic reaction.
NH4NO3 (s) → NH4+ (aq) + NO3- (aq)
- Dissolution / Endothermic Reactions / Energy Transformations / Lesson Plans / Solubility
- 1.3b / 5.4e / 6.2e / 6.5a / BIO.2a / CH.2h / CH.3e / CH.5g / PH.7a / PS.5b / PS.6b