### Select The Two Variables That Are Held Constant When Testing Boyle’S Law In A Manometer?

- Marvin Harvey
- 0
- 10

Temperature and number of molecules remain constant. An imaginary gas which perfectly obeys the gas laws.

### What two variables are held constant when testing Boyle’s Law?

In Boyle’s experiment, which two vari- ables were held constant? Both the temperature (T) and the number of moles of gas (n) were held constant in Boyle’s J-tube experiment.

#### What two variables does Boyle’s law relate?

The Relationship between Pressure and Volume: Boyle’s Law – As the pressure on a gas increases, the volume of the gas decreases because the gas particles are forced closer together. Conversely, as the pressure on a gas decreases, the gas volume increases because the gas particles can now move farther apart. Figure \(\PageIndex \): Boyle’s Experiment Using a J-Shaped Tube to Determine the Relationship between Gas Pressure and Volume. (a) Initially the gas is at a pressure of 1 atm = 760 mmHg (the mercury is at the same height in both the arm containing the sample and the arm open to the atmosphere); its volume is V,

- B) If enough mercury is added to the right side to give a difference in height of 760 mmHg between the two arms, the pressure of the gas is 760 mmHg (atmospheric pressure) + 760 mmHg = 1520 mmHg and the volume is V /2.
- C) If an additional 760 mmHg is added to the column on the right, the total pressure on the gas increases to 2280 mmHg, and the volume of the gas decreases to V /3 (CC BY-SA-NC; anonymous).

The Irish chemist Robert Boyle (1627–1691) carried out some of the earliest experiments that determined the quantitative relationship between the pressure and the volume of a gas. Boyle used a J-shaped tube partially filled with mercury, as shown in Figure \(\PageIndex \).

- In these experiments, a small amount of a gas or air is trapped above the mercury column, and its volume is measured at atmospheric pressure and constant temperature.
- More mercury is then poured into the open arm to increase the pressure on the gas sample.
- The pressure on the gas is atmospheric pressure plus the difference in the heights of the mercury columns, and the resulting volume is measured.

This process is repeated until either there is no more room in the open arm or the volume of the gas is too small to be measured accurately. Data such as those from one of Boyle’s own experiments may be plotted in several ways (Figure \(\PageIndex \)).

A simple plot of \(V\) versus \(P\) gives a curve called a hyperbola and reveals an inverse relationship between pressure and volume: as the pressure is doubled, the volume decreases by a factor of two. This relationship between the two quantities is described as follows: \ Dividing both sides by \(P\) gives an equation illustrating the inverse relationship between \(P\) and \(V\): \ or \ where the ∝ symbol is read “is proportional to.” A plot of V versus 1/ P is thus a straight line whose slope is equal to the constant in Equations \(\ref \) and \(\ref \).

Dividing both sides of Equation \(\ref \) by V instead of P gives a similar relationship between P and 1/ V, The numerical value of the constant depends on the amount of gas used in the experiment and on the temperature at which the experiments are carried out. Figure \(\PageIndex \) : Plots of Boyle’s Data. (a) Here are actual data from a typical experiment conducted by Boyle. Boyle used non-SI units to measure the volume (in.3 rather than cm 3 ) and the pressure (in. Hg rather than mmHg). (b) This plot of pressure versus volume is a hyperbola.

- Because PV is a constant, decreasing the pressure by a factor of two results in a twofold increase in volume and vice versa.
- C) A plot of volume versus 1/pressure for the same data shows the inverse linear relationship between the two quantities, as expressed by the equation V = constant/ P (CC BY-SA-NC; anonymous).

At constant temperature, the volume of a fixed amount of a gas is inversely proportional to its pressure

#### What is held constant for Boyle’s law?

Boyle’s Law – Robert Boyle (1627-1691), an English chemist, is widely considered to be one of the founders of the modern experimental science of chemistry. He discovered that doubling the pressure of an enclosed sample of gas, while keeping its temperature constant, caused the volume of the gas to be reduced by half.

- Boyle’s law states that the volume of a given mass of gas varies inversely with the pressure when the temperature is kept constant.
- An inverse relationship is described in this way.
- As one variable increases in value, the other variable decreases.
- Physically, what is happening? The gas molecules are moving and are a certain distance apart from one another.

An increase in pressure pushes the molecules closer together, reducing the volume. If the pressure is decreased, the gases are free to move about in a larger volume. Figure \(\PageIndex \): Robert Boyle. (CC BY-NC; CK-12) Mathematically, Boyle’s law can be expressed by the equation: \ The \(k\) is a constant for a given sample of gas and depends only on the mass of the gas and the temperature. The table below shows pressure and volume data for a set amount of gas at a constant temperature.

Table \(\PageIndex \): Pressure-Volume Data

Pressure \(\left( \text \right)\) | Volume \(\left( \text \right)\) | \(P \times V = k\) \(\left( \text \cdot \text \right)\) |
---|---|---|

0.5 | 1000 | 500 |

0.625 | 800 | 500 |

1.0 | 500 | 500 |

2.0 | 250 | 500 |

5.0 | 100 | 500 |

8.0 | 62.5 | 500 |

10.0 | 50 | 500 |

A graph of the data in the table further illustrates the inverse relationship nature of Boyle’s Law (see figure below). Volume is plotted on the \(x\)-axis, with the corresponding pressure on the \(y\)-axis. Figure \(\PageIndex \): The pressure of a gas decreases as the volume increases, making Boyle’s law an inverse relationship. (CC BY-NC; CK-12) Boyle’s Law can be used to compare changing conditions for a gas. We use \(P_1\) and \(V_1\) to stand for the initial pressure and initial volume of a gas.

## What 2 variables should be kept constant?

A researcher can change control variables, but they are kept constant in an experiment to show the relationship between the independent and dependent variables.

### What are the variables of Boyle’s law quizlet?

What are the variables in Boyle’s law? Volume and Pressure.

## What is the independent variable of Boyle’s Law?

Boyle’s Law Data Analysis Exercise: If you squeeze a sealed syringe, the volume of the air inside the syringe decreases. Conversely, when you release the pressure, the volume of the air inside the syringe increases. This relationship between the pressure of a gas and its volume was investigated by Robert Boyle.

The purpose of this data analysis exercise is to look at the data gathered by Boyle in 1662 and verify his conclusions. Boyle found that the pressure of a gas and its volume share an inverse relationship when at a constant temperature. Thus, doubling the pressure causes a gas’s volume to reduce by half.

PV = constant or P = constant x 1/V The constant can vary depending on the amount of gas and the temperature. Boyle’s experiments from 1662 provided data that, when graphed, illustrate this inverse relationship. This data was downloaded as an Excel file from http://webserver.lemoyne.edu/faculty/giunta/.

volume | pressure | inverse pressure | inverse volume |

48 | 29.125 | 0.03433 | 0.02083 |

46 | 30.5625 | 0.03272 | 0.02174 |

44 | 31.9375 | 0.03131 | 0.02273 |

42 | 33.5 | 0.02985 | 0.02381 |

40 | 35.3125 | 0.02832 | 0.02500 |

38 | 37 | 0.02703 | 0.02632 |

36 | 39.3125 | 0.02544 | 0.02778 |

34 | 41.625 | 0.02402 | 0.02941 |

32 | 44.1875 | 0.02263 | 0.03125 |

30 | 47.0625 | 0.02125 | 0.03333 |

28 | 50.3125 | 0.01988 | 0.03571 |

26 | 54.3125 | 0.01841 | 0.03846 |

24 | 58.8125 | 0.01700 | 0.04167 |

23 | 61.3125 | 0.01631 | 0.04348 |

22 | 64.0625 | 0.01561 | 0.04545 |

21 | 67.0625 | 0.01491 | 0.04762 |

20 | 70.6875 | 0.01415 | 0.05000 |

19 | 74.125 | 0.01349 | 0.05263 |

18 | 77.875 | 0.01284 | 0.05556 |

17 | 82.75 | 0.01208 | 0.05882 |

16 | 87.875 | 0.01138 | 0.06250 |

15 | 93.0625 | 0.01075 | 0.06667 |

14 | 100.438 | 0.00996 | 0.07143 |

13 | 107.813 | 0.00928 | 0.07692 |

12 | 117.563 | 0.00851 | 0.08333 |

This data was then analyzed using the inverse of the volume (1/V) that had been calculated. This new data was then plotted with (1/V) on the y-axis and pressure on the x-axis. This now provides a linear relationship. When a trendline was added, you can see that the R-squared value was 0.9999. If a relationship is inverse in one respect, it must also be inverse with regards to the other variable. Therefore, if inverse volume and pressure give a linear relationship, inverse pressure and volume must also give a linear relationship. The data manipulated earlier was now analyzed creating a graph with the inverse pressure (1/P) on the x-axis and volume on the y-axis. Using the three above graphs, you can easily see that the conclusions that Boyle drew based upon the data provided are accurate. There is an inverse relationship between a gas’s pressure and its volume. Return to Chem 501

#### What are the variables in this gas law?

The three variables for gas laws are: Volume, V. Pressure, P. Temperature, T.

## What variable is held constant?

The control variable remains constant throughout an experiment. The independent variable is manipulated during an experiment to hopefully produce the change on the dependent variable in the experiment.

### What factor held constant?

In an experiment, the independent variable is the factor that is changed and manipulated, whereas the dependent variable is what is measured. As the name suggests, the dependent variables are dependent on the independent variables. Finally, all the other factors kept the same/constant are control variables.

## Is temperature constant in Boyle’s law?

According to this law, at constant temperature, the pressure of the gas is inversely proportional to its volume.

### What are 2 controlled variables?

Examples of Controlled Variables – Temperature is a common type of controlled variable, If a temperature is held constant during an experiment, it is controlled. Other examples of controlled variables could be an amount of light, using the same type of glassware, constant humidity, or duration of an experiment.

### What are the two types of constant?

Use of the Constants in C – A constant is basically a named memory location in a program that holds a single value throughout the execution of that program. It can be of any data type- character, floating-point, string and double, integer, etc. There are various types of constants in C.

## Can a variable hold 2 values at the same time?

You could use a struct and handle the operations manualy. Otherwise, no a variable only has 1 value at a time.

## What are the 2 variables about the gas need to be kept constant when studying Charles Law to make it a fair experiment?

As per Charles’s law, the volume of a gas is directly proportional to its temperature (in the Kelvin scale) provided the amount of the gas and pressure remain constant. Hence, variables remain constant in Charles’s law: (1) amount of gas and (2) pressure.

#### What are two examples of Boyle’s Law?

1. Breathing – During respiration, our lungs make use of Boyle’s law. While inhaling, the lungs are filled with air; therefore, they expand. The volume increases, hence the pressure level goes down. Similarly, when the lungs are evacuated of air, they shrink; therefore, the volume reduces and the pressure increases. The change in pressure and volume is momentary and periodic in nature.

## What variable must be held constant in the combined gas law?

Combined Gas Law – To this point, we have examined the relationships between any two of the variables of \(P\), \(V\), and \(T\), while the third variable is held constant. However, situations do arise where all three variables change. The combined gas law expresses the relationship between the pressure, volume, and absolute temperature of a fixed amount of gas.

## What are 2 common examples of independent variable?

What Is an Independent Variable? What Is a Dependent Variable? – A variable is something you’re trying to measure. It can be practically anything, such as objects, amounts of time, feelings, events, or ideas. If you’re studying how people feel about different television shows, the variables in that experiment are television shows and feelings.

- If you’re studying how different types of fertilizer affect how tall plants grow, the variables are type of fertilizer and plant height.
- There are two key variables in every experiment: the independent variable and the dependent variable.
- Independent variable: What the scientist changes or what changes on its own.

Dependent variable: What is being studied/measured. The independent variable (sometimes known as the manipulated variable) is the variable whose change isn’t affected by any other variable in the experiment. Either the scientist has to change the independent variable herself or it changes on its own; nothing else in the experiment affects or changes it.

- Two examples of common independent variables are age and time.
- There’s nothing you or anything else can do to speed up or slow down time or increase or decrease age.
- They’re independent of everything else.
- The dependent variable (sometimes known as the responding variable) is what is being studied and measured in the experiment.

It’s what changes as a result of the changes to the independent variable. An example of a dependent variable is how tall you are at different ages. The dependent variable (height) depends on the independent variable (age). An easy way to think of independent and dependent variables is, when you’re conducting an experiment, the independent variable is what you change, and the dependent variable is what changes because of that.

## Is pressure or volume the independent variable?

Variables A variable is just a mathematical symbol for a measured (or measurable) property or quantity. Consider the ideal gas equation which regularly makes an appearance in chemistry and physics. It is not important what this equation says; we are interested only in how it represents the information.

- P = nRT / V (the ideal gas eqn) We say that the pressure, p, is the dependent variable and that there are three independent variables; the amount of gas, n, the termperature, T, and the volume of gas, V,
- As the name implies dependent variables depend upon other quantities.
- On the other hand, independent variables have no such dependence.

They are free to take whatever values they like and are uninfluenced by the other quantities we may be considering. In the ideal gas equation, the symbol R is not a variable. It is a constant, Its value does not change if we change the amount, temperature or volume.

## Which is independent and dependent variable?

Published on February 3, 2022 by Pritha Bhandari, Revised on December 2, 2022. In research, variables are any characteristics that can take on different values, such as height, age, temperature, or test scores. Researchers often manipulate or measure independent and dependent variables in studies to test cause-and-effect relationships.

The independent variable is the cause. Its value is independent of other variables in your study. The dependent variable is the effect. Its value depends on changes in the independent variable.

Example: Independent and dependent variables You design a study to test whether changes in room temperature have an effect on math test scores. Your independent variable is the temperature of the room. You vary the room temperature by making it cooler for half the participants, and warmer for the other half.

### What are the 2 variables about the gas need to be kept constant when studying Charles law to make it a fair experiment?

As per Charles’s law, the volume of a gas is directly proportional to its temperature (in the Kelvin scale) provided the amount of the gas and pressure remain constant. Hence, variables remain constant in Charles’s law: (1) amount of gas and (2) pressure.

#### Which quantity remains constant in both the cases of Boyle’s Law and Charles Law?

Answer: – Boyle’s Law states that pressure and volume have an inverse relationship. Boyle’s Law is based on the kinetic nature of matter. The temperature-volume connection is known as Charles Law. If the pressure and quantity of molecules stay constant, while the temperatures of molecules rises, the molecules travel faster, generating greater pressure just on container containing the gas & increasing the volume.