Chemical Measurements
Chemical Measurements
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In experiments, an ERROR is the difference between your result and the EXPECTED value.
We have two main error types: RANDOM ERRORS and SYSTEMATIC ERRORS.
This is when measured values vary randomly around the true value. Random error is very common in experiments due to HUMAN ERROR and RANDOM VARIATIONS. By taking many measurements and calculating the MEAN, we can overcome the issue of random errors.
Here's what might cause them:
This is when an issue in experimental design or EQUIPMENT causes the measured value to be consistently too high or consistently too low. These errors are harder to identify.
Some examples include:
Whenever a measurement is made there is always some uncertainty about the result obtained.
Uncertainty is all about how confident you are in your measurements. It's a number that tells you how much your results might be off by.
With ANALOGUE INSTRUMENTS, uncertainty is usually HALF of the smallest thing you can measure on it.
E.g. If your ruler's smallest division is 1 mm, your uncertainty is ±0.5 mm.
For DIGITAL INSTRUMENTS (like a digital clock), it's simpler: uncertainty is just the SMALLEST NUMBER it can display.
In experiments, an ERROR is the difference between your result and the EXPECTED value.
We have two main error types: RANDOM ERRORS and SYSTEMATIC ERRORS.
This is when measured values vary randomly around the true value. Random error is very common in experiments due to HUMAN ERROR and RANDOM VARIATIONS. By taking many measurements and calculating the MEAN, we can overcome the issue of random errors.
Here's what might cause them:
This is when an issue in experimental design or EQUIPMENT causes the measured value to be consistently too high or consistently too low. These errors are harder to identify.
Some examples include:
Whenever a measurement is made there is always some uncertainty about the result obtained.
Uncertainty is all about how confident you are in your measurements. It's a number that tells you how much your results might be off by.
With ANALOGUE INSTRUMENTS, uncertainty is usually HALF of the smallest thing you can measure on it.
E.g. If your ruler's smallest division is 1 mm, your uncertainty is ±0.5 mm.
For DIGITAL INSTRUMENTS (like a digital clock), it's simpler: uncertainty is just the SMALLEST NUMBER it can display.
