Graph 1 Lab

Data Analysis:
Graph 1 indicates the relationship between the dependent and the independent variable to be; as the concentration of sodium bicarbonate in the solution submerging the leaf discs is increased, the average rate of photosynthesis of the leaf discs increased in a linear trend. As it is the sodium bicarbonate which decomposes into carbon dioxide necessary for photosynthesis, it is reasonable to consider from Graph 1 that as carbon dioxide concentration of the solution increases, the rate of photosynthesis will also increase in a linear trend. Carbon dioxide concentration is shown to be directly proportional to rate of photosynthesis ([CO2] ∝ rate of photosynthesis). The line of best fit in Graph 1 illustrates that at 1% sodium hydroxide
A variable portion of the oxygen produced from each leaf disc was floating to the surface instead of staying attached to the leaf disc it was produced from. If the oxygen produced via photosynthesis is lost in the sodium bicarbonate solution, it will not be contributing to the force pushing the leaf disc to the surface of the sodium bicarbonate solution and therefore the time that the leaf discs take to reach the surface of the solution will increase. As all leaf discs were cut out using the same hole punch and therefore have the same cross section area and are orientated at the same direction to the light source, all leaf disks should have lost approximately an equal volume of oxygen from this error. This increased time for the leaf discs to ride to the surface of the sodium bicarbonate solution decreased the calculated rate of photosynthesis for all trials by an equal amount as the leaf discs will lose approximately the same amount of oxygen in each trial. This error will skew the calculated rate of photosynthesis to increase less than it should as the sodium bicarbonate concentration of the solution is increased. The effect of this error on the rate of photosynthesis calculated can be seen in Graph 1 as the line of best fit is slightly lower than the origin and is approximately -0.005 min-1 when the sodium bicarbonate concentration of the solution is 0%, the rate of photosynthesis should be 0min-1 when there is no sodium bicarbonate in the solution as there will be no carbon dioxide for photosynthesis to occur. This is a systematic error as it affects the accuracy of the rate of photosynthesis and decreases it for each