Dimensional Analysis
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Re: Dimensional Analysis
Dimensional analysis is basically just converting one unit to another unit. To do this you use a conversion factor. For example, using dimensional analysis, you can convert 1L to mLs by multiplying by the factor 1000 mL/1 L.
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Re: Dimensional Analysis
It's also helpful to memorize SI unit prefixes to help with unit conversions, especially since these won't be given to us for tests. I like to use the mnemonic device Good Models Know Donuts Can Make μ (You) Not Petite, which refers to Giga (9), Mega (6), kilo (3), deci (-1), centi (-2), milli (-3), micro (-6), nano (-9), pico (-12). Centi, milli, micro, and nano are probably used the most in chemistry.
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Re: Dimensional Analysis
Dimensional analysis is the process by which you convert one unit to another. For example, it can be something as simple as converting from meters to centimeters, in which you're increasing within a specific unit of length, or converting from degrees Celsius to Kelvin, in which you're converting from one measurement system to another.
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Re: Dimensional Analysis
Dimensional analysis is basically writing out all the units for numbers during calculation and trying to cancel them out at the end. It always starts with a "start unit", the unit you are given in problem; and it ends with the "end unit", the unit of the answer you are looking for. When you write the calculation with unit out and cancel the unit one by one, it actually guides your way from the start to the end of the problem. Most of the intermediate terms during calculation are multiplying the equation by 1, such as 1km/1000m or 1hour/60 minutes to reach the unit you want.
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Re: Dimensional Analysis
Hi! On top of what everyone else has said, I think the most helpful thing for me to refer back to is one of Dr. Lavelle's lectures on the Fundamentals. Specifically, in week 1, lecture 3, given on 10/8/20, Dr. Lavelle gives us a chart that is very helpful to dimensional analysis. The chart includes the prefix, the name, and the meaning of various SI base units that we should be familiar with. Hope this helps!
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Re: Dimensional Analysis
DA is a way of converting using the listed conversions as ratios to solve a problem. They are used to convert a number in 1 unit of measurement to another.
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Re: Dimensional Analysis
Dimensional analysis is a way of converting units. It can be useful to format entire problems with dimensional analysis, as it is an easy way of making sure all your units cancel and that you are left with the right units on top at the end.
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Re: Dimensional Analysis
dimensional analysis is using the conversion rates to change one unit to another.
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Re: Dimensional Analysis
I think it's very important, and in our best interest, to understand the significance of dimensional analysis. An arguably more "proper" manner of identifying the process of converting between unit measurements. By utilizing conversion factors, we can effectively convert between any desired unit so long as we are using the correct ratio between both units (could be as simple as dividing or multiplying between unit measurements). Be it from necessity or out of convenience, the conversion of units may aid in quantifying and measuring the substance or object in question.
Re: Dimensional Analysis
adding to everyone else's explanation of dimensional analysis, always make sure that when you are doing it the final units have canceled out to leave just one unit! (or combination of units such as g/mol)
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Re: Dimensional Analysis
For dimensional analysis, you want to multiple across so that the units on the top cancel with the units on the bottom. For example, if you want to convert grams to mols and you have 15 grams of h2o, you would multiple 15 g H2O (1 mol H2O/18g H2O) because you have the units g H2O on both top and bottom so they cancel.
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