Background: It would be very unadvisable to place a can of soup over a campfire without venting the can. As the can heats up, it may explode. The kinetic-molecular theory explains why. The air inside the rigid can of soup is given more kinetic energy by the heat coming from the campfire. The kinetic energy causes the air molecules to move faster and they impact the container walls more frequently and with more force. The increase in pressure inside may eventually exceed the strength of the can and it will explode. An additional factor is that the soup may begin boiling which will then aid even more gas and more pressure to the inside of the can. Paragraph: Two campers were in the woods over the week-end. They both had canned soup with them. Pete heated the can without venting it and it exploded, while Dan opened his can and heated it over the fire with no additional problems. Given the paragraph above, please answer correctly the following question: Which camper didn't observe that as the can heated up, it might have exploded?
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Answer: Dan

Background: Rainfall in an area is important because it influences the rate of weathering. More rain means that more rainwater passes through the soil. The rainwater reacts chemically with the particles. The top layers of soil are in contact with the freshest water, so reactions are greatest there. High rainfall increases the amount of rock that experiences chemical reactions. High rainfall may also carry material away. This means that new surfaces are exposed. This increases the rate of weathering. Paragraph: In an area east of the Rocky mountains, there are seasons of heavy rains and times of the year where it experiences sever droughts. This year the area has received record breaking amounts of rain. Given the paragraph above, please answer correctly the following question: Given a scientist is studying a desert with no rain all year, will he find the effects of weathering are high or low?
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Answer: low

Background: For example, if a solid pellet of NaOH is placed into a chamber of HCl gas, a relatively slow acid-base reaction will occur between gaseous HCl molecules and hydroxide ions on the surface of the pellet. If we were to grind the pellet into smaller pieces, it would greatly increase the total surface area, and therefore the overall reaction rate. Once ground up, many hydroxide ions that were on the interior of the pellet, where they were not exposed to any HCl molecules, will now be on the surface, where the necessary collisions can occur. Paragraph: In his chemistry lab David is experimenting with how NaOH and HCl gas reacts with each other. He conducted two experiments, experiment A and experiment B. In experiment A he used solid pellets of NaOH, but in experiment B he used ground NaOH. He was surprised to see the difference it made in his experiment. Given the paragraph above, please answer correctly the following question: In which experiment the interior hydorxide ion would not be exposed?
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Answer:
experiment A