Flashcards in The Alkaline Metals And The Halogens Deck (12):
Name the alkali metals
Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rub), Caesium (Cs) and Francium (Fr)
Name some trends in the alkali metals when you go down the periodic table
Atoms get bigger, metals get softer, metals get more dense, metals get more reactive
Give some observations when you add: a) lithium; b) sodium; and c) potassium to water
A) fizzes, floats, moves around while it gradually gets smaller, if there is universal indicator in the water then the water goes blue.
B) all the same as lithium except faster, melts into a ball shape
C) all that potassium does except even faster and with a lilac flame
Write the word equation for the reaction between lithium and water (note, it will be the same with all the other alkali metals but with different metals)
Lithium + water -> lithium hydroxide + hydrogen
Write the symbol equation for the reaction between lithium and water (note, it will be the same with all the other alkali metals but with different metals)
2-Li (s) + 2-H2-O (l) -> 2-Li-O-H (aq) + H-2 (g)
Why do the alkali metals react more aggressively as you go down the group
The atoms get larger as you go down, this means that the outer shell electron gets further away from the nucleus and is shielded by other shells, the further away a negative electron is from the positive nucleus, the easier it can be lost in reactions.
How can you test for metal ions
Dip a nichrome wire in hydrochloride acid and then put it in the flame to clean it. Dip it into hydrochloride acid again and then into the substance. Heat the wire in a non-roaring, non-luminous Bunsen flame and note the flame colour. These are examples of some cations.
K+ = Lilac; Na+ = Yellow; Li+ = Red; Ca2+ = Orange-red; Cu2+ = Blue-green
Describe what happens to the halogens as the RAM inceaces
The state at room temperature changes from gas to liquid to solid
The colour of vapour becomes darker
The boiling and melting point increases
How do halogens react with compounds of other halogens
A more reactive halogen can displace a less reactive halogen from it’s compound.
Eg) chlorine + sodium iodide = reaction
Iodine + sodium chloride = no reaction
Chlorine + sodium chloride = no reaction
Write the word equation of chlorine reacting with sodium iodide (note, it will be the same with all similar reactions).
Chlorine + sodium iodide -> sodium chloride + iodine
Write the symbol equation of chlorine reacting with sodium iodide (note, it will be the same with all similar reactions).
Cl2 + 2NaI -> 2NaCl + I2