Question

read this! when designing an experiment, you need to consider three types of variables. the independent variable is changed by the researcher by design. this variable is sometimes called the \manipulated variable.\ the dependent variable is what changes as a result of the change in the independent variable. this variable is sometimes called the
esponding variable.\ in some cases more than one dependent variable is considered. the third category involves controlled variables. these are variables that you think might change the outcome of the experiment, but since you are not studying them, you need to keep them constant in each trial. 11. identify the independent, dependent, and controlled variables for the experiments that produced the data shown in model 2 and model 3. model experiment variables independent dependent controlled alka - seltzer® and vinegar boiling points of alcohols read this! a well - written research question states the independent and dependent variables for an experiment. for example, a student investigated the effect of the deicer, magnesium chloride, on vegetation on the sides of highways. her research question was, \what is the effect of magnesium chloride solution concentration on the growth of rye grass?\ 12. write a research question, using the format suggested in the read this! box, for the experiments in model 2 and 3. alka - seltzer® and vinegar — boiling points of alcohols— 13. a student wonders, \will changing the volume of alcohol in a boiling point experiment change the boiling point of the liquid?\ identify the variables that should be considered in this experiment. independent dependent controlled

Explanation:

Step1: Identify variables for Alka - Seltzer and Vinegar experiment

Independent: Amount/concentration of Alka - Seltzer or Vinegar. Dependent: Reaction rate/amount of gas produced. Controlled: Temperature, volume of vinegar, brand of Alka - Seltzer.

Step2: Identify variables for Boiling Points of Alcohols experiment

Independent: Type of alcohol. Dependent: Boiling point. Controlled: Atmospheric pressure, volume of alcohol sample, heating rate.

Step3: Write research questions

Alka - Seltzer and Vinegar: What is the effect of the amount/concentration of Alka - Seltzer on the reaction rate with vinegar?
Boiling Points of Alcohols: What is the effect of the type of alcohol on its boiling point?

Step4: Identify variables for the new boiling - point experiment

Independent: Volume of alcohol. Dependent: Boiling point of the liquid. Controlled: Type of alcohol, atmospheric pressure, heating rate.

Answer:

11.
Alka - Seltzer and Vinegar:
Independent: Amount/concentration of Alka - Seltzer or Vinegar
Dependent: Reaction rate/amount of gas produced
Controlled: Temperature, volume of vinegar, brand of Alka - Seltzer

Boiling Points of Alcohols:
Independent: Type of alcohol
Dependent: Boiling point
Controlled: Atmospheric pressure, volume of alcohol sample, heating rate

12.
Alka - Seltzer and Vinegar: What is the effect of the amount/concentration of Alka - Seltzer on the reaction rate with vinegar?
Boiling Points of Alcohols: What is the effect of the type of alcohol on its boiling point?

13.
Independent: Volume of alcohol
Dependent: Boiling point of the liquid
Controlled: Type of alcohol, atmospheric pressure, heating rate