Video Transcript
The black line on the graph below
shows the concentration of gas produced during a reaction between an acid and a
metal. The reaction is then repeated using
an identical piece of metal but with a higher concentration of acid. Which line on the graph most likely
represents this repeated experiment?
We are told in the question that a
reaction between an acid and a metal is carried out twice. The first reaction is represented
by the black line on the graph. We need to determine which line,
the red or the blue, represents the second reaction. The graph shows the concentration
of gas produced by the reaction over time. The measure of how reactant or
product concentration, mass, or volume changes over time is the rate of
reaction. So the lines on a graph of
concentration of gas produced over time represent the rate of reaction.
We can think of rate of reaction as
the speed of a chemical reaction. When the rate of reaction is high,
the gas will be produced more quickly and the line will be steeper. The opposite is also true. When the rate of reaction is low,
the gas will be produced more slowly and the line will be less steep.
We are told in the question that
the second reaction uses an identical piece of metal as the first, but a higher
concentration of acid. So we need to know how a higher
concentration of acid will affect the rate of reaction. Chemical reactions occur when
particles successfully collide with one another. If we can increase the number of
collisions between particles, then the chance of a successful collision will
increase and the rate of reaction will increase.
In the box, we have a certain
concentration of pink and orange particles that collide with one another and the
walls of the container. If the concentration is increased,
then there are more particles available to collide. So there will be more total
collisions. And if the number of collisions
increases, then the rate of reaction increases. So a reaction using a higher
concentration of acid will have a higher rate of reaction and the graph of
concentration of gas produced versus time will have a steeper line.
Therefore, the line on the graph
that represents the repeated experiment using a higher concentration of acid is the
blue line.
