Metric system density

The concept of kinematic viscosity is the outgrowth of the use of a head of liquid to produce a flow through a capillary tube. The coefficient of absolute viscosity, when divided by the density of the liquid is called the kinematic viscosity. In the metric system, the unit of viscosity is called the stoke and it has the units of centimeters squared per second. One one-hundredth of a stoke is a centistoke. 

Note The values of density and specific gravity, in metric system, are numerically equal, i.e., when expressed in g/cc, the values of density and specific gravity are the same. For example, a density of 1.2 g/cc equals specific gravity of 1.2. 

Figure 44-5. Density of water from 0 to 375c C. (Metric system)...

The original idea of the metric system was that either approach would provide the same unit of metric volume. Unfortunately, it did not work because of the subtle differences in density caused by subtle differences in temperature. Thus, the kilogram-based milliliter equaled 1.000,027 cubic centimeters. Because of the discrepancy, the International System for Weights and Measures had to make a choice between which approach would be accepted to obtain volume measurements, and the nod was eventually given to the cubic length technique. The use of liters and milliliters in volumetric ware is therefore misleading because the unit of volume measurement should be cubic meters (cubic centimeters are used as a convenience for smaller containers). The International System of Units (SI) and the ASTM accept the use of liters and milliliters in their reports, provided that the precision of the material does not warrant cubic centimeters. Because the actual difference in one cubic centimeter is less than 3 parts in 100,000, for most work it is safe to assume that 1 cm3 is equal to 1 mL. 

After years of study by a committee appointed by Louis XVI62, in 1799 Bonaparte63 adopted for use throughout France the metric system of units The unit of time was defined as 1 /86,400 of a mean solar day the meter was defined as the 40,000,000th of the mean earth diameter and the gram was defined as the mass of 1 cubic centimeter of liquid water at the temperature of its maximum density (4 °C). This defined the cgs system. 

The density of a material is the ratio of mass to volume. In the metric system it is expressed in grams per cubic centimeter (g/cm or g cm—for liquids and solids and in grams per liter (g/i) for gases. The solubility of a substance in a particular solvent is the amount of substance (the solute) that will dissolve in a given amount (usually 100 g) of the solvent. 

Sometimes the specific gravity is used instead of density. The specific gravity is the ratio of the weight of a specimen of a substance to the weight of the same volume of water. The speciific gravity has nearly the same numerical value as the density in the metric system. 

The physical properties of water are used to define many physical constants and units. The freezing point of water (saturated with aii at 1 atm pressure) is taken as 0° C, and the boiling point of water at 1 atm is taken as 100° C. The unit of volume in the metric system is chosen so that 1 ml of water at 3.98° C (the temperature of its maximum density) weighs 1.00000 gram. A similar relation holds in the... 

For gases the standard reference material is dry air and its density is taken at the same temperature and pressure for which the density of the gas is given. The distinction between specific gravity and density must he kept clearly in mind. In the metric system, the density of water is essentially equal to one. Consequently, specific gravities and densities have substantially the same numerical values in this system of units. However, this is not generally true. 

This experiment is intended to be an exercise in the application of significant figures and the metric system to the measurement of a physical property, density. It is intended to support the classroom discussion of these topics. Waste antifreeze can be disposed of through an automotive shop at a college or through an automotive service station. 

SECTION 1.4 Measurements in chemistry are made using the metric system. Special emphasis is placed on SI units, which are based on the meter, the kilogram, and the second as the basic units of length, mass, and time, respectively. SI units use prefixes to indicate fractions or multiples of base units. The SI temperature scale is the Kelvin scale, although the Celsius scale is frequently used as well. Density is an important property that equals mass divided by volume. 

Nominal linear density of the yarn measures the coarseness of the yarn in units of dedtex, i.e. mass per unit length. In the metric system, 10 000 m of 1 dtex yam weighs 1 g. Higher decitex value indicates a coarser yarn. Filament linear density, ), is calculated using following equation ... 

The density of water is 1.00 g/ml at 4°C. The metric system of measuring liquid density is based on this number. When comparing the density of liquids, generally they can be compared to water. This makes it easier to figure out whether liquids will mix or not, since two liquids of very different densities don t usually combine. 

It was mentioned in Section 1-4 that the density of a substance is the mass (weight) of a unit volume of the substance in the metric system, grams per cubic centimeter or kilograms per cubic meter. 

A quantitative science requires the making of measurements. Any measurement has limited precision, which you convey by writing the measured number to a certain number of significant figures. There are many different systems of measurement, but scientists generally use the metric system. The International System (SI) uses a particular selection of metric units. It employs seven base units combined with prefixes to obtain units of various size. Units for other quantities are derived from these. To obtain a derived unit in SI for a quantity such as the volume or density, you merely substitute base units into a defining equation for the quantity. 

The revised metric system is called the International System of Units (abbreviated SI, from the French Systeme Internationale d Unitds). Table 1.2 lists the seven SI base units. All other units of measurement can be derived from these base units. The SI unit for volume, for instance, is derived by cubing the SI base unit for length. The prefixes listed in Table 1.3 are used to denote decimal fractions and multiples of SI units. This enables scientists to tailor the magnitude of a unit to a particular application. For example, the meter (m) is appropriate for describing the dimen.sions of a classroom, but the kilometer (km), 1000 m, is more appropriate for describing the distance between two cities. Units that you will encounter frequently in the study of chemistry include those for mass, temperature, volume, and density. 

Volume is based on length hence, ihe metric unit is 1 cubic meter, m , The metric system also recognizes the LITER, 1, which is 10 m . The liter was formerly defined as the volume of 1 kg of pure water at the temperature of its maximum density (3.98 C) at 1 standard atmosphere. Since the liter is an approved metric unit, so are its multiples and fractions, of which the most common is the milliliter, ml. 

In the metric system, the density of a liquid or a solid is most often given as the number of grams in 1 mL, or grams per milliliter. In this text, when calculating density, the mass will be expressed in grams and the volume in milliliters or cubic centimeters. The densities of some liquids and solids are given in Table 2.7. 

In Section 2.6.1, we note that the density of liquids changes with temperature, decreasing with increasing temperature (as the volume expands) and increasing with decreasing temperature (as the volume contracts). The density of water is equal to 1.000 g/mL at 4°C, a temperature that is near the freezing point of water. The link between the mass and volume domains then is that 1 g of water is the same as 1 mL of water at 4°C. Again, this shows the creativity and convenience that is exhibited by the metric system. Water has been used as a standard substance to create links and to set-up entire domains of measurement in the metric system. 

In the metric system, the densities of solids and liquids are usually expressed as grams per cubic centimeter (g/cm ) or grams per milliliter (g/mL). The density of a gas is usually stated as grams per liter (g/L). Table 2.9 gives the densities of some common substances. 

The density of steel is 0.283 Ibm/in. In the SI metric system, this measurement converts to approximately... 

Chapter 2. Chemistry and Measurements, looks at measurement and emphasizes the need to understand numerical relationships of the metric system. Significant numbers are discussed in the determination of final answers. Prefixes from the metric system are used to write equalities and conversion factors for problem-solving strategies. Density is discussed and used as a conversion factor. 

---