Sodium (Na\text{Na}Na) and potassium (K\text{K}K) are two alkali metals in Group 1 of the Periodic Table. Both react vigorously when added to a trough of water. \nState\nState\nState two observations that would be made when a small piece of sodium is added to water.
Potassium is more reactive than sodium. State one observation that is made with potassium but not with sodium.
Complete and balance the chemical equation for the reaction of sodium with water:
2Na+2H2O→‾+‾ 2\text{Na} + 2\text{H}_2\text{O} \rightarrow \underline{\hspace{2cm}} + \underline{\hspace{2cm}} 2Na+2H2O→+After the reaction of sodium with water is complete, a few drops of universal indicator are added to the solution. State the color of the indicator and give the formula of the ion responsible for this color.
An oxide of copper can be reduced to metallic copper by heating it in a stream of hydrogen gas.\nIn\nIn\nIn an experiment, 12.7 g of copper is obtained by completely reducing 14.3 g of this copper oxide.
[Relative atomic masses: Cu=63.5\text{Cu} = 63.5Cu=63.5, O=16\text{O} = 16O=16]
\nCalculate\nCalculate\nCalculate the mass of oxygen lost from the copper oxide during this reduction.
Determine the empirical formula of the copper oxide by calculating the amounts, in moles, of copper atoms (Cu\text{Cu}Cu) and oxygen atoms (O\text{O}O).