If a stress of 10.0 MPa is applied to an elastomeric material at 20°C. After 25 days, the stress decreases to 5.0 MPa. Calculate the relaxation time for this material.

How many moles of oxygen are required to burn 4.4 x 10^23 moles of C8H18

Draw the structure of the organic product of the reaction below. ΝΗ, + + са N=N 0 × Click and drag to start drawing a structure.

In amorphous polymers, the glass transition temperature is Tg. Indicate what occurs at temperatures below and above Tg.

If we know the molecular weights of a given polymer, what is the number-average molecular weight and the weight-average molecular weight? molecular weight range number fraction weight fraction 8000-16000 0.05 0.02 16000-24000 0.16 0.10 24000-32000 0.24 0.20 32000-40000 0.28 0.30 40000-48000 0.20 0.27 48000-56000 0.07 0.11

If two chains have the same molecular weight, they should contain the same number of monomers and have the same degree of polymerization. Correct?

Polymer chains of poly(methyl methacrylate) and Teflon are available, both of which have the same molecular weight. Does one of the two chains have more monomers than the other? (Atomic weights: C: 12, O: 16; H: 1; F: 19).

Indicate exactly (% and T) where the eutectic point is located Temperature (°C) 2200 2000 Liquid 1800 1600 Cristobalite + Liquid 40 60 80 18 4000 3800 Liquid 3600 + Alumina 3400 1890 ± 10°C Mullite (ss) Mullite (ss) + Liquid Alumina Mullite (ss) 1587 ± 10°C Mullite (ss) + Cristobalite 1400 0 20 40 (SiO2) L 3200 3000 2800 2600 60 80 100 (Al2O3) Composition (wt% Al2O3) Temperature (°F)

18. Explain with the help of partial molecular orbitals the difference between an acceptor and a donor ligand. 19. Construct molecular orbital diagram consistent with [Ni(NH))6]² 20. Draw the molecular orbital diagrams of (a) (b) [FeCle] [Fe(CN)6]³ Determine whether the complexes are high spin or low spin What is the total number of molecular orbitals of each complex ion Calculate the ligand field stabilization energy and the spin only magnetic moment of each complex ion.