# Help understanding an experiment set up

• dRic2
In summary, the paper is discussing a pyrolysis experiment where a known flow rate of 99.5% isobutene and 99.998% nitrogen were introduced into a 6mm ID quartz reactor. The mole fraction of isobutene, O2, and N2 needs to be calculated, but the paper does not mention the amount of O2 in the mixture. It is later clarified that the experiment is actually about pyrolysis, not combustion, so no O2 is needed and the inlet mixture is likely 50% isobutene and 50% N2.

#### dRic2

Gold Member
Hi, I'm reading a paper about combustion and I can't understand the composition of the inlet mixture. Here's what the paper says:

"A known flow rate of the isobutene (Matheson, TriGas, 99.5%) in nitrogen (General Air, 99.998%) was introduced into a 6mm ID quartz reactor that was heated in an electric furnace..."

I need to calculate the mole fraction of isbutene, O2, and N2 but I don't understand the above sentence. Any suggestion would be of great help!

PS. isobutene = isobutylene

PSS: I find very strange that in a combustion experiment is not mentioned the amount of O2 in the mixture... Maybe I'm overlooking something, but I didn't find anything else in the paper

PSS: I forgot an important part: there is a line that says "N2/iC4H8 = 50/50 % mol"

Can you give the reference?

dRic2 said:
I find very strange that in a combustion experiment is not mentioned the amount of O2 in the mixture... Maybe I'm overlooking something, but I didn't find anything else in the paper

Check whether the paper is about "combustion" or "pyrolysis".

berkeman and dRic2
Lord Jestocost said:
Check whether the paper is about "combustion" or "pyrolysis".
Oh, I'm an idiot...

It says pyrolysis so no O2 is needed, then I assume the inlet mixture is just 0.5 isobutene and 0.5 N2, right ?

## What is the purpose of setting up an experiment?

The purpose of setting up an experiment is to test a hypothesis or answer a research question in a controlled and systematic manner. By carefully designing and executing the experiment, scientists can gather data and draw conclusions about the relationship between variables.

## What are the key components of an experiment set up?

The key components of an experiment set up include the independent variable (the factor being manipulated), the dependent variable (the outcome being measured), control variables (factors that are kept constant), and the experimental group (subjects or conditions that receive the independent variable) and the control group (subjects or conditions that do not receive the independent variable).

## How do you determine the sample size for an experiment?

The sample size for an experiment should be large enough to accurately represent the population being studied. This can be determined through statistical power analysis, which takes into account factors such as the desired level of significance, effect size, and variability in the data.

## What is the importance of randomization in an experiment set up?

Randomization is important in an experiment set up because it helps to reduce bias and ensure that the results are not influenced by external factors. By randomly assigning subjects to different groups, researchers can be more confident that any differences observed between groups are due to the independent variable and not other variables.

## How do you control for confounding variables in an experiment?

Confounding variables are factors that can influence the outcome of an experiment but are not accounted for in the study design. To control for these variables, scientists can use techniques such as randomization, matching, and statistical analysis to ensure that the results are not affected by these variables.