Volume metric units

The basic unit for weight is grain (gr) and that of volume is minim (m). Unlike the metric units, the amount is expressed in Roman numerals after the apothecaries symbol. For example, V2 grain is expressed as gr ss but not V2 gr. Twenty minims is expressed as m xx. Sometimes physicians also use Arabic numerals in the apothecary system. For example 12 ounces can be written as l XII or 4 ounces as 4 l. Tables 2.4 and 2.5 show the relationships... 

In general, a combination of volume per unit of time and/or energy would be a most useful metric, but one should also consider these materials in terms of their intrinsic hazards, just as for any process reagent, solvent, or reactant... 

Properties of Staple Fibers. Fiber diameters range from AAA lo G (Table 2). with the largest production volume in the range C—G. Thermal conductivity of gluss-liber products is influenced by fiber diameter, density or compactness of the liber mass, and temperature conditions. Generally, thermal eunductiv itv ranges between 0.20 and 0.80 (Blu)lin.)f(hr>Ht It F). In metric units. I his is 0.02y and 0.1 15 watl/meter-Kclvin W/ni K. 

Although organic chemistry is a mature subject, different energy units, different abbreviations for metric units of volume and different systems of nomenclature, for example, are still commonly used. We have been consistent within chapters in these respects and follow common usage within each particular area, but uniformity has not been imposed upon the book as a whole. 

C = coefficient of heat conductivity measured in heat units per unit time per unit of packing volume per deg temperature difference usual units are cal per sec per deg C per cc m = a constant for limestone packings, m = 0.0073 for iron ore, 0.0105 anthracite and other coals, 0.0050 blast-furnace charge, 0.0072. The values are in metric units. q = volume of gas flow per unit-time per square unit of cross-sectional packing area, expressed as liters per sec per sq cm T = temperature, deg abs, C = fractional voids (dimensionless) d = diameter of particles, cm... 

In addition to solubility, the concentration of a dissolved substance in a given solvent can be expressed in parts per notation, when low concentrations of a particular substance are still considered significant. In these cases the metric system is the most convenient way to express values as metric units increase stepwise as ten, hundred, thousand and so on. Typically this is given on the basis of mass but it can also be expressed by volume, mass/volume (m/v) ratio, or number of moles. For example A milligram (1 mg or 0.001 g) is one part per thousand of a gram (1000 mg or 1 g) or one part per million (ppm) of a kilogram (1000 000 mg or 1000 g). 

The cubic meter (m ) is the primary unit of volume in SI. A smaller unit, the liter, is the primary unit of volume in the metric system. The abbreviation for hter is L. We need to know both the cubic meter and the liter. Table 2.3 summarizes the primary metric units of distance, mass, and volume. 

The only metric units that are cubed are units of length— any unit ending in m— to give a unit of volume. 

I The metric units used to report volumes may involve liters or the cube of a length unit. 

The metric unit of volume is the liter (1), which is approximately 1.06 U.S. quarts. The milliliter (ml), equal to 1/1000 1, is usually used as the unit of volume in the measurement of liquids in chemical work. The milliliter is defined as the volume occupied by exactly 1 g of water at 3.98° C (the temperature at which its density is the greatest) and under a pressure of one atmosphere (that is, the normal pressure due to the weight of the air). 

From R. W. Haywood, Thermodynamic Tables in SI (Metric) Units, Cambridge University Press, London, 1968. V = specific volume, 7 = specific internal energy, and f = specific enthalpy. Note kJ/kg X 0.4303 = BtWIb. ... 

Minutes are permitted to remain in the metric system for convenience or for historical reasons, even though they don t conform strictly to the rules. The minute, hour, and day, for example, are so customary that they re still defined in the metric system as 60 seconds, 60 minutes, and 24 hours— not as multiples of ten. For volume, the most common metric unit is not the cubic meter, which is generally too big to be useful in commerce, but the liter, which is one thousandth of a cubic meter. For even smaller volumes, the milliliter, one thousandth of a liter, is commonly used. And for large masses, the metric ton is often used instead of the kilogram. A metric ton (often spelled tonne in other countries) is 1,000 kilograms. Because a kilogram is about 2.2 pounds, a metric ton is about 2,200 pounds 10% heavier than an American ton of 2,000 pounds. Another often-used, non-standard metric unit is the hectare for land area. A hectare is 10,000 square meters and is equivalent to 0.4047 acre. 

Figure 2-3 shows the relationship between different SI volume units, including the cubic decimeter (dm ). The metric unit for volume equal to one cubic decimeter is a liter (L). Liters are used to measure the amount of liquid in a container of bottled water or a carbonated beverage. One liter has about the same volume as one quart. For the smaller quantities of liquids that you will work with in the laboratory, volume is measured in milliliters (mL). A milliliter is equal in volume to one cubic centimeter. Recall that milli means one-thousandth. Therefore, one liter is equal to 1000 milliliters. 

This equation states that the reaction rate is equal to the rate of change of concentration with respect to time—all in consistent units. Rates expressed using concentration changes require the assumption of constant volume. The units of the rate become lbmol/(h ) and gmol/(s L) in the engineering and metric (SI)... 

In analytical chemistry, we often determine the amount of chemical species from mass measurements. For such measurements, metric units of kilograms (kg), grams (g), milligrams (mg), or micrograms (pg) are used. Volumes of liquids are measured in units of liters (L), milliliters (mL), and sometimes microliters (pL). 

Volumes are often measured in liters or milliliters in the metric system. One liter (1 L) is one cubic decimeter (1 dm ), or 1000 cubic centimeters (1000 cm ). One milliliter (1 mL) is 1 cm In medical laboratories, the cubic centimeter (cm ) is often abbreviated cc. In the SI, the cubic meter is the basic volume unit and the cubic decimeter replaces the metric unit, liter. Different kinds of glassware are used to measure the volume of liquids. The one we choose depends on the accuracy we desire. For example, the volume of a liquid dispensed can be measured more accurately with a buret than with a small graduated cylinder (Figure 1-13). Equivalences between common English units and metric units are summarized in Table 1-7. 

Volumetric gas rates are defined either at normal conditions (0°C and latm or 1013 mbar of absolute pressure) or at standard conditions in English units standard conditions are defined at 60°F (15.56°C) and 1013 mbar, while in metric units standard conditions are defined at 15°C and 1013 mbar. There is practically no difference between the two standard conditions, but care should be used not to confuse them with normal conditions. The abbreviations cf and cm are commonly used to denote ft and m, respectively. Volumes defined at standard conditions... 

List the metric units without prefixes and the corresponding abbreviations for length (meter, m), mass (gram, g), volume (liter, L), and energy (joule, J). (Section... 

The metric unit of volume is the liter, abbreviated L, originally defined as the volume of a cube 1 dm on each edge. The SI unit of volume is the cubic meter, m. That volume is too large for ordinary laboratory work, so smaller related units are used—the cubic decimeter (equal to a liter), or the cubic centimeter (equal to a milliliter). A comparison of these units is presented in Table 2-3. 

Some textbooks use the classical metric unit, the liter, and its related volumes others use the SI unit, cubic meters, and its related volumes. We must know both. For simplicity, after this chapter, we will use liters (L) in this book rather than cubic decimeters, because almost everyone is familiar with liters and its subdivisions from everyday use. (How much does a 2-liter bottle of cola cost )... 

Fig. 2-2 Relationships of Si and Metric Units of Volume. (Not drawn to scale.)...

The standard metric unit of volume, the space occupied by an object, is the liter. A liter is the volume occupied by 1000 grams of water at 4 degrees Celsius (°C). The volume, 1 liter, also corresponds to ... 

The standard metric unit of time is the second. The need for accurate measurement of time by chemists may not be as apparent as that associated with mass, length, and volume. It is necessary, however, in many applications. In fact, matter may be characterized by measuring the time required for a certain process to occur. The rate of a chemical reaction is a measure of change as a function of time. 

To do this we will load a helpful package called Miscellaneous Units from Mathematica. We also want graphs of the predicted catalyst mass as function of time, the theoretical level of catalytst in the reactor as a function of time, and the actual level that has been measured in the reactor at a few times during the loading process. Finally, we can compute the catalyst cost in flowing into the reactor volume per unit time. Here we calculate the mass flow in per unit time in metric units as well as the volume and cross-sectional area of the reactor. 

You ll find yourself having to convert between household and metric units when you calculate a patient s input and output volume and when you provide home healthcare to a patient. There, you ll use a teaspoon, tablespoon, or cups measured in ounces to administer medication. 

One of the most fundamental measurements that one has to make is the concentration of solid material (whether clay, flint, stone, or feldspar) in a suspension or slip. There are many ways in which this concentration can be expressed, but the method universally adopted in industry is that of slip density, expressed as the weight of slip per unit volume. In metric units this quantity will be in grams per ml., or in British units ounces per pint. The conversion factor of 20 stems from the fact that 1 pint of water x g per ml. = 20jc oz per pint. 

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