Lithium (Li\text{Li}Li) and potassium (K\text{K}K) are two alkali metals in Group 1 of the Periodic Table. Both react with water.
State two observations that would be made when a small piece of lithium is added to water.
Potassium is more reactive than lithium. State one observation that is made with potassium but not with lithium.
Complete and balance the chemical equation for the reaction of lithium with water:
2Li+2H2O→‾+‾ 2\text{Li} + 2\text{H}_2\text{O} \rightarrow \underline{\hspace{2cm}} + \underline{\hspace{2cm}} 2Li+2H2O→+After the reaction of lithium with water is complete, a few drops of phenolphthalein indicator are added to the solution. State the color of the indicator and give the formula of the ion responsible for this color.
Lithium reacts with oxygen to form an oxide. In an experiment, 2.98 g2.98\text{ g}2.98 g of this lithium oxide is obtained by completely reacting 1.38 g1.38\text{ g}1.38 g of lithium metal with oxygen. [Relative atomic masses: Li=6.9\text{Li} = 6.9Li=6.9, O=16.0\text{O} = 16.0O=16.0]
Calculate the mass of oxygen that reacted with the lithium.
Determine the empirical formula of the lithium oxide by calculating the amounts, in moles, of lithium atoms (Li\text{Li}Li) and oxygen atoms (O\text{O}O).
