Help... In the BLUE scenarios below, describe errors in the experimental designs and how those errors can be can be corrected.

Scenario 4 Metals and Rusting IronIn chemistry class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting. Allen hypothesized that less rusting would occur with the more active metals. He placed the following into 4 separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, and (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals, and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water.

Scenario 5 Perfumes and Bees’ BehaviorJack read that certain perfume esters would agitate bees. Because perfume formulas are secret, he decided to determine whether the unknown Ester X was present in four different perfumes by observing the bee’s behavior. He placed four saucers, each containing 10 mL of a different perfume, in a semicircle 3 m from the hive entrance. He recorded the time required for the bees to emerge and made observations on their behavior. Jack repeated the experiment every hour for five hours. All repetitions were conducted on the same day as the weather conditions changed from cool and humid in the morning to hot and dry in the afternoon.