Experiment #2
question: do different types of music affect how well a person can do his/her homework?
hypothesis: music that does not have a strong beat makes concentrating on a homework assignment easier.
music with heavy beats makes concentration more difficult.
experiment:
sara lilia pulled out four different cd's to find out which type her to finish her homework the
fastest. the first cd was rock, the second reggaeton, the third classical, and the fourth was cumbia. she chose a
math assignment that required concentration.
sara lilia used a stopwatch with an alarm to make sure that she only listened to each cd for 5 minutes.
each time the alarm went off, sara lilia recorded how many problems she was able to finish.
at the end of the experiment, she found that she was able to concentrate the most with the classical
music, then the rock, and the cumbia. she noticed that she did not concentrate much at all with the reggaeton
and felt like dancing and singing along instead of working.
a. what was the independent variable?
b. what was the dependent variable?
c. what was the control? _
d. was there a constant variable?

Explanation:

An independent variable is a variable in which does not rely on how other variables. It is usually cause in an experiment. From Sara Lilia experiment, we can identify the different music genres as her independent variable.

The dependent variable here is her ability to concentrate in her study. Here, we should know that the dependent variable is often the result of the effects of the independent variable.

There is no control in the experiment. In the controlled set up, we would have put all other know factors that would make concentrations easier into consideration. It could be the environment, the arrangement of the room and a particular time of the day. None of such was stated in the experiment.

The constant variable is the variable that was held fixed throughout the experimental procedure. Here the time of study was fixed at 5minutes. What would happen to concentration if this time was shorter or much more?

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2