1, understand the grade of chemical reagents and the principle of storage
2、Master the standardized use of glass instruments
3、Specify the function of each glass apparatus
This experiment is from Mudanjiang Medical College undergraduate 5-year laboratory guide for testing majors.
Operation method
Laboratory experiments on the use of laboratory equipment
Materials and Instruments
Pure water Move I. Experimental materials: different grades of chemical reagents Measuring materials Measuring cylinders Volumetric flasks Pipettes (pipettes without graduated two-lined tubes Graduated pipettes Micropipettes) Pipette balls For more product details, please visit Aladdin Scientific website.
Measuring cylinders, volumetric flasks, straws, pipettes, suction balls, scales, thermometers, pipette bottles.
II. Experimental steps:
1. According to the markings on the reagent bottles, explain the grade of the reagent and how to store it.
2, the use of glass measuring device: in accordance with the labeling on the glass measuring device, divided into measuring in and out of a certain amount of liquid more than 5 times, to achieve proficiency in the use of, pay attention to the suction of liquid when the scale reading and the angle of the liquid when measuring.
Calibrate pipettes by constant weight method.
Experimental purpose; master constant weight calibration of glass gauges
Experimental equipment: one-millionth of the balance, pure water, pipette, temperature sh Pipette bottle
Experimental principle: Vt = Wt/dt
Experimental steps:
1. Adjust the one-millionth balance.
2. Take 20 ml of water with the pipette being examined and fill it into the pipette bottle in which the mass has been weighed.
3. weigh the total mass to obtain the mass of water
4. measure the temperature of the water with a thermometer to determine the density of the water at that temperature.
5. Calculate the volume of water.
6. calculate the weighing error to determine if it is within the allowable range.