Holding and storing liquids

Test tubes
Both 'normal' and the much smaller 'semi-micro' test tubes are used for small-scale reactions and tests, e.g. qualitative analysis or solvent selection for recrystallization.

Beakers
Beakers are used for general purposes, e.g. heating a non-volatile solvent while the solute dissolves, 'working up' a reaction where liquid/solid products need to be accessible for manipulation (stirring with a glass rod), or titrations using electrodes where a wide opening is essential. The volume graduations on the side are inaccurate and should only be used where approximations will suffice. The lip on the beaker is specifically designed to aid quantitative transfer of solutions.

Conical (Erlenmeyer) flasks
These can be used for general purposes, but they have more specialist applications. The narrow mouth and sloping shoulders reduce losses on stirring/swirling and evaporation and make them easier to seal. The absence of a lip does not favour quantitative transfer: useful in manual titrations and recrystallizations. Volume markings are approximate.

Bottles and vials
These can be used when the solution needs to be sealed for safety, storage or to prevent evaporation or oxidation. They usually have a screwtop, plastic cap or stopper or a ground-glass stopper and come in various styles and sizes: from 2.5 L glass bottles used for storing large volumes of solutions to small plastic-capped vials (5mL) for saving small amounts of reaction products.

Seal the vessels in an appropriate manner, using a stopper, cap or sealing film such as Parafilm^® or Nescofilm^®, bearing in mind the nature of the contents - sealing film should only be used for water solutions since it dissolves in some organic solvents and plasticizers may be extracted. Do not use corks, they are not air-tight. Do not use rubber bungs to seal containers containing organic solvents, they can swell even over a short period of time making removal very difficult.

You should clearly label all stored solutions including all relevant hazard information.