Hydrogen Flashcards
Why is H2 a gas?
Extremely low melting/boiling points as very weak London dispersion forces (small electron clouds)
Why is H2 unreactive?
The sigma covalent bond is very strong so it needs a lot of energy to break it and a catalyst.
What hydrides do s block elements normally form?
s block elements are very electropositive so form ionic hydrides.
What is the H- anion called?
A hydride
What hydrides do d and f block elements normally form?
interstitial hydrides because the electronegativity is higher than s block but still lower than hydrogen.
What are interstitial hydrides?
Ones which have a metallic bond.
What elements form covalent hydrides?
Ones with high electronegativities
What are intramolecular forces?
Ones which hold atoms together within a molecule
What are intermolecular forces?
Forces between molecules
Is hydrogen bonding intermolecular or intramolecular?
Intermolecular.
What elements does hydrogen bonding happen with?
N, O, F
Why do hydrogen bonds happen?
Big difference in electronegativity between H and N,O or F means e- density drawn away from H meaning ‘bare proton’ can form hydrogen bond with lone pair of near electronegative element
Are the products of group 1 metals and oxygen acidic or basic?
Basic
Are oxides of electronegative elements more likely to be acidic or basic?
Acidic
What are Bronsted acids?
Proton donors
