Volumetric Flask – Glass – 250ml PK2.
These volumetric flask is made of borosilicate glass and packed in a pack of 2. The capacity of the flasks is 250ml, with a tolerance of +/- 0.30ml. The volumetric flasks are fitted with a chemical resistance polyethylene stopper as per DIN 12664. The socket size is 14/23.
Volumetric flasks are used for precise dilutions and preparation of standard solutions. The marking indicates the volume of liquid contained when filled up to that point and is calibrated to contain 250ml of liquid at 20 Degrees C.
Volumetric flasks should not be exposed to direct heat e.
g. hotplates of Bunsen burners. The volumetric flasks can be cleaned in automatic dishwashers and autoclaving at 121DegreesC is acceptable and will not affect the accuracy. Always hold the volumetric flask in vertical position when reading the meniscus and keep it at eye level to avoid parallax errors, for the most accurate results.
Thermal properties of the glassware:
Coefficient of thermal expansion of Lab Glass is low, the temperature gradient are consequently low and the glass can withstand higher gradients and also sudden temperature changes/thermal shocks. All glassware is annealed under strictly controlled conditions to ensure minimal residual stress in the he products. The typical thermal properties of Lab Glass glassware is given below:
Coefficient of Linear Expansions = 32.5 x 10-7/ DegreesC
Strain Point = 515 DegreesC
Annealing Point = 565 DegreesC
Softening Point = 820 DegreesC
Specific Heat = 0.2
Thermal Conductivity Cal/cm3 DegreesC/sec = 0.0027
Chemical Durability of the glassware:
Lab Glass Glassware is highly resistance to water, neutral and acid solutions, concentrated acids, chlorine, bromine iodine and organic matters. It can withstand repeated dry and wet sterilisation without surface deterioration and subsequent contamination. Only hydrofluoric acid, very hot phosphoric acid and alkaline solutions increasingly attack the glass surface with rising concentration and temperature.
