Mean molecular mass

Multiplying both denominators by M0, which is the (mean) molecular mass of a structural unit, and dividing each member by 2 gives... 

The feed composition is 27.4 per cent CS2 and 72.6 per cent CCI4 so that the mean molecular mass of the feed is given by ... 

The NaOH, solution contains 100 kg/m3 NaOH. The mean molecular mass of liquid is ... 

The ratio of frequencies upon substitution of for O is taken to be proportional to the square root of the ratio of the mean molecular masses. 

It is denoted by C and depends on the flame temperature, mean molecular mass of the combustion products and propellant formulation. It is a fundamental parameter which gives the energy available on combustion and can be used to compare the efficiency of different chemical reactions independently of the Pc. For propellants, the value of C ranges between 1200 and 1600 ms-1. It is determined by firing a propellant grain in a motor and evaluating the area under the P-t profile and using Equation 4.11. 

G. Protein molecular mass from electrospray. The enzyme lysozyme33 exhibits MHJ[+ peaks at mlz = 1 789.1, 1 590.4, 1 431.5, 1 301.5, and 1 193.1. Follow the procedure of Table 22-3 to find the mean molecular mass and its standard deviation. 

A fairly good correlation between the storage modulus and the relaxation rate (1/T2) was observed. Both methods gave similar values for the mean molecular mass of network... 

Figure 10.3 Mean molecular mass between chemical crosslinks and trapped chain entanglements Mc+e in a cured mixture of a poly(ethylene glycol) diacrylate (PEGDA) and 2-ethylhexyl acrylate (EHA) as a function of the EHA content [52]. Mc+e values were determined from (1/T2s)max and the plateau modulus (see Figure 10.2). A substantial difference in Mc+e value, as determined by these two methods at low crosslink density, is caused by the effect of network defects which decrease volume average network density determined by DMA (see Section 10.3). The molecular mass of PEGDA (Mn = 700 g/mol) is indicated by an arrow. The molecular mass of network chains in cured PEGDA is about three times smaller than that of the initial monomer. The molecular origin of this difference is discussed in Section 10.3...

A variant of the concept of Cardenas and O Driscoll is the approach of Marten and Hamielec [40]. According to these authors, k, is proportional to the difusion coefficients, which are a function of the viscosity of the medium. This viscosity depends on the weight average mean molecular mass and thus kt can be written as... 

Turner et al. [41-43] do not consider reduced coil mobility with increasing polymer concentration as decisive. Under these conditions, macromolecules behave as rigid balls, mutually hardly penetrable the probability of radical encounter decreases. The onset of autoacceleration is also ascribed to mutual coil entanglement which only occurs at and above the critical polymer concentration Cc and a certain minimum mean molecular mass A (0.5 < a < 1). The product of these critical quantities is constant... 

We can now estimate the theoretical gel point in this system the mean molecular mass of this mixture is calculated to be j 1000+j 465 = 786 (g I mol) for the equimolar case (k = 1). Considering the dilution effect (33 w / w %) by dioxane, it follows that y 2All mol. The polyethylene oxide molecule of interest is composed of 70 skeletal bonds on average. Due to this long backbone along with the dense solution, it can be approximated that the structural unit follows Gaussian statistics. With the Flory characteristic constant [6], C = (r2)/nf2=4,for polyethylene oxide in the 0 regime, one has... 

If we assume a mean molecular mass of the element as equal to 100 (in this case the... 

The heat capacity and entropy of GeSe(g) were calculated by the review from the molecular parameters of Ge Se(g) given by Herzberg [79HUB/HER] using the usual non-rigid rotator, anharmonic oscillator approximation. The parameters were scaled to the mean molecular mass by the procedures outlined in [50HER]. No excited states were considered since they all lie above 30,000 cm and do not affect the properties below 3000 K. The calculated values are selected ... 

By chromatography on silica gel 60 at a column temperature of -40 °C the 8x mixture has been separated into six fractions the mean molecular mass of the sulfur rings dissolved in these fractions ranged from 1100 (first fraction) to 733 (last fraction). In other words, 8 must contain rings with up to 35 atoms at least [88]. A more sophisticated chromatographic separation will be described in the following section. 

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