The Lab Report Format

Purpose State the reason for doing the lab. You will be able to identify the purpose based on the question you are given to solve. – Question: What temperature provides the ideal condition for yeast to grow? – Purpose: To identify the ideal temperature for yeast to grow in.

Hypothesis Follow the format: – If…..then….because Example: – Question: What will happen to plant growth if acid rain falls on them? – Hypothesis: If acid rain falls on plants then the plant will not grow because acids are corrosive and will destroy the plants roots.

Materials List all of the chemicals and equipment used: Chemical ListEquipment List – Zinctest tube (1) – 0.1 M NaOH500mL beaker Include the number or size of equipment Include concentration of chemicals of necessary

Procedure Write the procedure in Past Passive – Past Tense: Write the procedure as though it has already happened. – Passive Voice: Avoid using personal pronouns like I, we, our. You will be given instructions, and you must write them in past passive tense.

Procedure Wrong: I measured 100ml of hydrochloric acid using a graduated cylinder Correct: Wrong: Weigh 5 grams of sodium bicarbonate using an electronic balance. Correct:

Diagram Include a simply labeled diagram on blank paper illustrating how the equipment was set up for you experiment.

Incorrect-labels are not aligned

Observations Should include qualitative ( ie. colour ) and quantitative ( ie. mass ) Do not include inferences or interpretations of your data. – Leave this for your analysis and discussion

Discussion and Analysis You will usually be given discussion questions to answer and have calculations to do. Be thorough and show all of your work What does “Justify you answer” mean? – Always use YOUR data to support your choices.

Conclusion Includes a brief summary of what you learned You should refer to the purpose Do not state whether your hypothesis was correct or incorrect!

Scientific Error

Mistakes will be made during an experiment, however what counts is what you can learn from it. Think about how to make the experiment better to get more consistent results.

Types of Errors Types of Errors to IncludeTypes of errors not to include 1.Systematic Errors Errors caused by the way the experiment was designed 2.Random Errors Unpredictable errors that you have little control over 1.Human Errors Mistakes made by the scientist that can be fixed easily

Examples of Errors Human Error: – Spilling chemicals – Not cleaning the equipment – Not following the instructions correctly – Not measuring the chemicals correctly

Examples of Errors Random Error: – slight variations in the volume of a liquid while reading the meniscus in the graduated cylinder – Air flow over an electronic balance causing the mass to be slightly different. All of these errors are reduced by doing multiple trials, and taking averages of your data!

Examples of Errors – Systematic Errors: Something is wrong with the equipment used or the way the equipment was used. When measuring liquids, ensure you are using an appropriate size of graduated cylinder. – If you are measuring 5ml of liquid, a 100ml graduated cylinder will give not provide accurate samples for each trial. This can cause your result to be different each time » The next time you will want to use a 10ml graduated cylinder.