A student performs a reaction twice. In the second trial, he increases the temperature of the reaction and notes that the reaction happens more quickly. The student concludes that this means the reaction was endothermic. What is wrong with the student's reasoning?

Higher temperature increases reaction rates for both endothermic and exothermic reactions.
An endothermic reaction would not speed up at higher temperatures.
Temperature does not affect the rate of a reaction.
The higher temperature in the second trial actually lowered the activation energy of the reaction.

Alice added sodium chloride to water and stirred the water for several minutes. alice is most likely trying to demonstrate that ionic compounds a. are hard. b. can dissolve. c. are clear. d. can melt.

•• al and bert are jogging side-by-side on a trail in the woods at a speed of 0.75 m/s. suddenly al sees the end of the trail 35 m ahead and decides to speed up to reach it. he accelerates at a constant rate of 0.50 m/s2, while bert continues on at a constant speed. (a) how long does it take al to reach the end of the trail? (b) once he reaches the end of the trail, he immediately turns around and heads back along the trail with a constant speed of 0.85 m/s. how long does it take him to meet up with bert? (c) how far are they from the end of the trail when they meet?

Aphysical change is a change in the size, shape,, or stafe of matter true or false