Melting point- the temperature at which a substance has changed from a solid to a liquid
freezing- the temperature at which a substance chanes from liquid to a solid
boiling point- the temperature at which a substance changes from a liquid to a gas phase
Answer:9.18 m/s
Explanation:
The average speed for the entire trip is found ......total distance/total time. Remember r*t=d, so divide both sides by t and get r = d/t.
So the cyclist went 800+500+1200 m = 2500 m for total distance.
10t =800 leads to t=80 sec
5t=500 leads to t=100 sec
13t = 1200 leads to t = 92.3 sec
total time is 272.3 sec
Average speed for the entire trip is 2500 / 272.3 = 9.18 m/s
Answer:
1. They can tell that a reaction has taken place if there is formation of gas bubbles in the test tube as well as if the metal dissolves in the acid solution
2. To determine which metal is more reactive, they would compare how fast each reaction occurs. The most reactive metal would have the fastest rate of reaction with a vigorous formation of bubbles, whereas the least reactive metal will have the slowest rate of reaction.
Explanation:
1. Metal which are more electropositive than hydrogen displace hydrogen from dilute acids with the formation of the salt of the metal and evolution of hydrogen gas. Therefore, the formation of gas bubbles in the test tube indicates that a reaction is taking place.
2. The rate of formation of the gas bubbles as well as the time taken for the reaction to come to a completion by the dissolution of the metal in the acid indicates which metal is more reactive. The most reactive metal would have the fastest rate of reaction with a vigorous formation of bubbles, whereas the least reactive metal will have the slowest rate of reaction.
However, the rate of the reaction is also affected by the concentration of the acid used. The higher the concentration of the acid, the faster the reaction rate.
