Pasangan elektron bebas nitrogen, muatan, dan link polimer
Diperkenalkan| English | Makna |
|---|---|
| amine/ˈæmaɪn/ | Amine |
| zwitterion/zwɪˈtɪərɪən/ | Zwitterion |
| polyamide/ˌpɒlɪˈeɪmaɪd/ | Poliamida |
| hydrogen bonds/ˈhaɪdrədʒn bɒndz/ | Ikatan hidrogen |
Follow the nitrogen lone pair
- An amine 胺 accepts H⁺ through its nitrogen lone pair. Alkyl groups generally increase electron density and basicity relative to ammonia.
- In phenylamine, interaction with the ring makes the lone pair less available. Its basicity is lower.
Keep the nitrile carbon
- Reducing propanenitrile with LiAlH₄ in dry ether then work-up gives propan-1-amine. The nitrile carbon remains in the chain.
- Nitrobenzene instead needs Sn/HCl to make phenylammonium salt; alkali then releases phenylamine.
Berapa banyak atom karbon yang tersisa ketika propanonitril direduksi menjadi amina?
Difficulty 2/5 · 140 coins + a small bonus on first completion today
Ketiga karbon, termasuk karbon nitril, tetap ada.
Track both amino-acid groups
- A zwitterion 两性离子 has NH₃⁺ and COO⁻ groups and zero net charge. In strong acid, COO⁻ becomes COOH.
- In strong alkali, NH₃⁺ becomes NH₂ while COO⁻ remains. Glycine is achiral because its central carbon has two H atoms.
Glycine’s alkaline form is H₂NCH₂COO⁻, with net charge −1, not the zero-charge zwitterion.
Manakah bentuk utama glisin dalam alkali kuat?
Difficulty 1/5 · 100 coins + a small bonus on first completion today
Alkali menghilangkan proton amonium sementara gugus karboksil tetap terdeprotonasi.
Glisin bersifat akiral karena karbon pusat memiliki dua atom _____ yang identik.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
Dua substituen hidrogen identik mencegah terbentuknya pusat kiral dengan empat gugus berbeda.
Locate the polymer backbone
- A polyamide 聚酰胺 has –C(=O)–NH– links in its backbone. Condensation produces those links and a small molecule.
- Poly(propenamide) instead opens C=C by addition. Its amide side groups do not make the reaction condensation.
Setiap polimer dengan gugus samping amid terbentuk melalui kondensasi.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
Polipropenamida adalah polimer adisi dengan gugus samping amida.
Explain properties through interactions
- Polyamide N–H and C=O groups form hydrogen bonds 氢键 between chains. These help hold fibres together.
- Poly(ethenol) OH groups hydrogen-bond to water, supporting suitable water-soluble laundry-bag applications.
The presence of an amide group alone does not classify the polymerisation route.
Locate the nitrogen lone pair and its availability before comparing bases. Read the actual reacting groups and links to distinguish addition from condensation polymerisation.
Gugus manakah yang membentuk ikatan hidrogen antar rantai poliamida?
Difficulty 2/5 · 140 coins + a small bonus on first completion today
Gugus N–H dapat mendonorkan dan oksigen karbonil dapat menerima ikatan hidrogen.