Key Concepts and Summaryĭensity relates a substance’s mass and volume. Density can be used to calculate volume from a given mass or mass from a given volume. Often, the unit of the given quantity must be first converted to the appropriate unit before applying density as a conversion factor. Make sure the mass units are the same, or the volume units are the same, before using density to convert to a different unit. What is the density of the metal?Ĭare must be used with density as a conversion factor. It is placed in 200.0 mL of water, and the water level rises to 742.1 mL. Chemistry Conversion Factors and Constants METRIC CONVERSION FACTORS Prefix Abbreviation Conversion Factor For Example' For Example' Mega- M 1000000 10 6 1 Megabyte 1 x 10 bytes 1 byte 10-6 Megabytes kilo- k 1000 10 3 1 kilometer 1000 meters 1 meter 0.001 kilometers deci- d 0.1 10-1 1 deciliter 0. What volume should be measured to obtain 10.0 g of the liquid?ī) A cube of metal has a mass of 1.45 kg. Energy Units Converter Enter your energy value in the box with the appropriate units, then press 'tab' or click outside of the input box. Thus, in this case we must invert it.ĥ.00\ \ruleĪ) Isopropyl alcohol has a density of 0.785 g/mL. Look at the density value as a “conversion factor” (2.50 g/mL) and arrange it so it CANCELS what you already know. If a 5.00 g sample has a density of 2.50 g/mL, what volume does it occupy? Note how the mass units cancel, leaving the volume unit, which is what we’re looking for. Thus, if we want to know the volume of 45.9 g of gold, we would set up the conversion as follows: This reciprocal density is still a useful conversion factor, but now the mass unit will cancel and the volume unit will be introduced. In so doing, we move not only the units but also the numbers: For example, to convert from bar to pounds per square inch you would multiply by 100000 then divide by 6894.757. When we want to use density to convert from mass to volume, the numerator and denominator of density need to be switched-that is, we must take the reciprocal of the density. If you multiply a value times either of these fractions, its value will be unchanged.
This could be written as: 1g / 1000 mg 1 or 1000 mg / 1 g 1. Consider the unit conversion: 1 g 1000 mg. That is, the density value tells us that we have 19.3 grams for every 1 milliliter of volume, and the 1 is an exact number. Unit conversions work the same way, except '1' is expressed in the form of a conversion factor or ratio. Take the density of gold, for example:Īlthough this was not previously pointed out, it can be assumed that there is a 1 in the denominator: We have already demonstrated that the number that goes with density normally goes in the numerator when density is written as a fraction. Use the density from Table 1 “Densities of Some Common Substances” as a conversion factor to go from volume to mass:ĭensity can also be used as a conversion factor to convert mass to volume-but care must be taken.
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