Products significant figures

Evaluate the product Uj Mj for each class this is required for the calculation of both and M. Values of this quantity are listed in the third column of Table 1.4. From SjnjMj and Sjnj, = 734/0.049 = 15,000. The matter of significant figures will not be strictly adhered to in this example. 

Economic Aspects. In 1994, there were 16 operating hardboard and hardboard siding mills in the United States. Production was 1.535 x (2) in standard hardboard products. These figures do not include the significant quantities of door skin products made, for which production quantities are not tabulated. Production of hardboards has been relatively stable in recent years, considering them as a group. There have been a few new mill closings and a few mill start-ups. In addition, imports of hardboard have also become more common in recent years. 

Factors which may affect the cost of coal upgrading are environmental considerations such as toxicity, hazardous waste disposal, and carcinogenic properties (131). These and other environmental problems from process streams, untreated wastewaters, and raw products would figure significantly into the cost of commercialization. 

Compression. Compression is the simplest and the least effective of the four recovery methods. It was the first process used for the recovery of hydrocarbon Hquids from natural gas but is used only ia isolated cases. The most significant appHcation of the compression process is for gas-cycling plants where the natural gas Hquids are removed and the remaining gas is returned to the production formation. Figure 3 is a schematic of a typical gas-cycle plant. 

Treatment of poly(vinyl alcohol) with aldehydes and ketones leads to the formation of poly(vinyl acetals) and poly(vinyl ketals), of which only the former products are of any commercial significance Figure 14.7). 

To be specific, consider the data for 17.0 grams of ammonia gas at 25°C, as presented in Table 4-1 (p. 51). These data show that PV = 24.5, but a complete statement should include both the uncertainty and the range over which the data are known to apply. In this case the uncertainty is 0.7 and the range is 0.2-2 atmospheres pressure. It would not be safe, from these data alone, to assume that the pressure-volume product is constant to four significant figures, PV = 24.50. Neither would it be safe to assume that the pressure-voiume product is constant outside the range of pressure studied, 0.2-2.0 atmospheres. Remember, a generalization is reliable within... 

The value with the fewest significant figures determines the number of significant figures in a product. 

The dual-pump system is used when a large amount of gasoline is to be recovered. Separate gasoline and water pumps are used. The dual-pump system significantly reduces the amount of water that must be treated. Water pumps are placed at a depth lower than the water table to be able to establish a cone of depression, and the gasoline pumps draw out the gasoline that floats into the depression on the top of distorted water table for product recovery (Figure 18.6b). 

The hydrothermal ageing of Fe-ZSM5, which represents practical operating conditions, resulted in the production of N20 at intermediate temperatures in the presence of N02 in the gas feed (Figure 9.26) [57], For Cu-ZSM5, the addition of N02 to the feed increased the N20 production significantly, the maximum value of 111 ppm found at 250°C. 

The rate of reaction that is measured is the initial rate, i.e. that which is measured over the first few seconds or minutes of the reaction, before a significant proportion of the substrate has been used or the product formed (Figure 3.6). The rate is known as the enzyme activity. 

There is often a large variation in values from source to source— in some cases, some orders of magnitude. For diis reason, only one significant figure (at most) is given before the exponent. A table of solubility products for many sulphides based on a reevaluated value for the second dissociation constant of H2S is given in Ref. 1. The values in that study are typically some orders of magnitude lower than the ones shown here. 

Multiplying or dividing Round the product or quotient so that it has the same number of significant figures as the least-precise measurement — the measurement with the fewest significant figures. 

Q, Express the following product with the proper number of significant figures ... 

Following the rules of significant-figure math, the first step yields 24.4 feet-1-5.02 feet-1.348 feet. Each product or quotient contains the same number of significant figures as the number in the calculation with the fewest number of significant figures. 

Nozzle port size is also selected to accomodate desired spray rate and viscosity. The position of the nozzle is very significant. In top spray coating operations, the nozzle is positioned to spray liquid counter currently to the flow of product (see Figure 3). In the Wurster system, the nozzle sprays concurrently with the well organized flow of substrate (see Figure 4), and in the rotor technique, the nozzle sprays concurrently in the spiralling bed of product (see Figure 5). 

Multiplication or division. The product or quotient should be rounded off to the same number of significant figures as the least accurate number involved in the calculation. Thus, 0.00296 x 5845 = 17.3, but 0.002960 x 5845 = 17.30. However, this rule should be applied with some discretion. For example, consider the following multiplication ... 

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