Alkali Metals and Chemical Reactions Flashcards
Define reactivity in chemistry.
How readily a substance undergoes chemical reaction.
In alkali metals, the as atomic number increases which properties also increase?
Reactivity, atomic radius, ionic radius and density
In alkali metals, the as atomic number increases which properties decrease?
Melting point, ionization energy, electronegativity and boiling point.
Define electronegativity
χ or electronegativity is the tendency for an atom to attract atoms towards themselves.
In the following reaction relating to alkali metals, what does it create: 2Na + 2(H2O)
2(NaOH) + H2
In the following reaction relating to alkali metals, what does it create:
2Li + 2(H2O)
2(LiOH) + H2
In the following reaction relating to alkali metals, what does it create: Na (when it gives away an electron)
Na^+ + e^-, Reduction reduction potential: 2.71 volts
What is reduction potential?
A tendency for something to acquire or lose electrons.
In the following reaction relating to alkali metals, what does it create:
Li (When it loses an electron)
Li^+ + e^- Reduction potential: 3.05 volts
In the following reaction relating to alkali metals, what does it create:
2Na + Cl2
2(NaCl)
In the following reaction relating to alkali metals, what does it create: 4Li + O2
2(Li2O)
In the following reaction relating to alkali metals, what does it create:
4Na + (Limited) O2
2(Na2O) (Sodium Oxide)
In the following reaction relating to alkali metals, what does it create: 2Na + (Excess) O2
Na2O2 (Sodium Peroxide)
In the following reaction relating to alkali metals, what does it create: K + O2
KO2 (Potassium Superoxide)
What does oxidation state mean?
Hypothetical charge of an ion atom if all of its bonds to other atoms were ionic.
What does the prefix “per” mean in chemistry?
The very highest oxidation state (hydrogen peroxide means hydrogen + oxygen at its highest oxidation state)
What does the prefix “super” mean in chemistry?
Indicates that a chemical compound contains a specific element in higher proportion than usual.
Why are alkali metals with higher atomic numbers more reactive?
For reference let’s use lithium and cesium:
Lithium only has two shells meaning the pull on the electron is stronger, thus making it harder for it to be given away. Cesium has 6 shells, meaning the nucleus pull is a lot weaker, allowing it to be given up easier.
A second reason is that the melting point of lithium is 180c while for cesium is only around 29c. Molten versions of atoms are much more reactive then their solid counterparts.
