6 Making a standard solution

Making a solution Weighing can be made more accurate by weighing bottle again after it has been emptied into the beaker- or alternatively the weighing bottle could be washed and washings added to the beaker. Remember to fill so the bottom of the meniscus sits on the line on the neck of the flask. With dark liquids like potassium manganate it can be difficult to see the meniscus. •Weigh required mass of solute in a weighing bottle. • Tip contents into a beaker and add100cm3 of distilled water. Use a glass rod to stir to help dissolve the solid. •Sometimes the substance may not dissolve well in cold water so the beaker and its contents could be heated gently until all the solid had dissolved. •Pour solution into a 250cm3 graduated flask via a funnel. Rinse beaker and funnel and add washings from the beaker and glass rod to the volumetric flask. •make up to the mark with distilled water using a dropping pipette for last few drops. • Invert flask several times to ensure uniform solution.