To investigate the weathering of marble due to acid rain.
The larger the surface area the quicker the reaction. Because there will be more surface area or room to collide with the marble chip particles therefore resulting in a quicker reaction. The smaller the surface area, the slower the reaction will be as there will be fewer particles so less chance of a collision and a lower rate of reaction.
• 1x Test Tube Rack
• 2x Test tubes
• 1x Delivery tube (U bend) with rubber stopper
• Lime water
• 1M HCI
• 2 Large marble chips
• 4-5 Small marble chips
• 1x Stopwatch
• 1x Black card with blue tack
Step 1- Arrange test tubes and delivery tube.
Step 2- Arrange black cardboard behind the rack (this is to provide a contrast to the reaction) Step 3- Fill the unstoppered test tube with lime water, making sure to fully cover the end of the delivery tube. Step 4- Place the small marble chips in the other test tube, pour on a small quantity of HCI. Step 5- Quickly restopper the test tube.
Step 6- Use the stop watch to time how long it takes the lime water to go cloudy. Step 7- Repeat using the large marble chips.
• Any reaction involving a solid can only take place at the surface of the solid. • If the solid is split into several pieces, the surface area increases. What effect will this have on rate of reaction? • This means that there is an increased area for the reactant particles to collide with. • The smaller the pieces, the larger the surface area. This means more collisions and a greater chance of reaction.
• Marble chips are made of calcium carbonate. They react with hydrochloric acid to produce carbon dioxide. • The effect of increasing surface area on the rate of reaction can be measured by comparing how quickly the mass of the reactants decreases using marble chips of different sizes. • Risk Assessment: