PH 5.5-9.0 Test Indicator Paper Litmus Strips 100pcs/box

Test paper using method:

1. test solution: take a piece of paper on the surface of the dish or glass, to be soaked in liquid glass rod or a dropper to the central strip, observe the change of the color and color, color contrast, determine the nature of the solution.

2., test the nature of the gas: first distilled water test paper wetting, stick to one end of the glass rod, with glass stick test paper close to the gas, observe the change of color, determine the nature of the gas.

3. note:

• (1) the test paper can not be directly extended into the solution.
• (2) test paper can not touch test tube mouth, bottle mouth, conduit mouth, etc..
• (3) when determining the pH of a solution, the test paper shall not be wetted with distilled water beforehand because the wetting test paper is equivalent to the diluted solution being tested, which results in inaccurate measurements. The correct method is to use the glass stick dipped in the solution to drip in the middle of the test paper. After the test paper has changed color, compare with the standard color ratio card to determine the pH of the solution.
• (4) after taking out the test paper, the container for holding the test paper shall be tightly covered so as not to be contaminated by some gas in the laboratory.