Suggest the reason sodium is kept beneath oil.
State the name used for a reaction in which a substance burns.
State the flame colour observed when sodium burns.
Write a chemical equation for the reaction that occurs when sodium burns in air to form sodium oxide.
Complete the dot-and-cross diagram to show the electron arrangement and charges of the ions in sodium oxide.
Explain in terms of proton transfer what the term base means.
State a pH value that shows a strong alkali is present.
State the colour of methyl orange in aqueous sodium hydroxide.
Calculate the concentration of NaOH(aq) formed, in g/dm$^3$, when 0.345 g of sodium is added to 50.0 cm$^3$ of distilled water. Assume the volume does not change. Use these steps:\n• Find the number of moles of Na added.\n• Work out the number of moles of NaOH formed.\n• Calculate the concentration of NaOH in mol/dm$^3$.\n• Find the $M_r$ of NaOH and use it to calculate the concentration of NaOH in g/dm$^3$.
Name the reaction type in which a solid is produced from two solutions.
State the colour of this solid product.
Name this solid product.
Write the ionic equation for the reaction. Include state symbols.