When a solid substance is involved in a chemical reaction, only the matter at the surface of the solid is exposed to other reactants. If a solid has more surface area, more of it is exposed and able to react. Therefore, increasing the surface area of solid reactants increases the reaction rate. Look at the hammer and nails pictured in the Figure below . Both are made of iron and will rust when the iron combines with oxygen in the air. However, the nails have a greater surface area, so they will rust faster.
Sam and Beth both had a bad cold. Sam dug around in the medicine cabinet until he found some alka-seltzer cold tablets and grab a back for each of them and 2 glasses of water. Sam dropped his tablets straight into the water. Beth crushed her tablets into a powder then poured the powder into her glass of water.
Would breaking up his tablets increase or decrease the rate of reaction for Sam's tablets?