(a)
Chloroethene has a melting point of -154 °C
All types of PVC melt at temperatures over 100 °C
Explain why PVC melts at a higher temperature than chloroethene.

How many moles are present in 10.5 grams of nacl?

Challenge question: this question is worth 6 points. as you saw in problem 9 we can have species bound to a central metal ion. these species are called ligands. in the past we have assumed all the d orbitals in some species are degenerate; however, they often are not. sometimes the ligands bound to a central metal cation can split the d orbitals. that is, some of the d orbitals will be at a lower energy state than others. ligands that have the ability to cause this splitting are called strong field ligands, cnâ’ is an example of these. if this splitting in the d orbitals is great enough electrons will fill low lying orbitals, pairing with other electrons in a given orbital, before filling higher energy orbitals. in question 7 we had fe2+, furthermore we found that there were a certain number (non-zero) of unpaired electrons. consider now fe(cn)6 4â’: here we also have fe2+, but in this case all the electrons are paired, yielding a diamagnetic species. how can you explain this?

If cos x =sin(20 + x) and 0 < x < 90, the value of x is > 3 , 35 , 350answer is 35, free 50 points