0
The reason you heat the test tube before weighing it is because of the residual moisture on the test tube itself. The weight of the glass itself will not change, but if there is moisture inside the tube, it could distort your readings. Therefore, you heat the test tube to evaporate any moisture remaining in the test tube to get an accurate weight measurement.
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
Why do sample should be keep in dark place for 30minutes in determination of iodine value?
to avoid the light go through in the sample and keep the sample cool also.
From the thermal decomposition of copper carbonate how can you use conservation of mass to measure the amount of carbon dioxide produced?
Before thermal decomposition, weigh the mass. Thermally decompose. Allow to cool Re-weigh. The difference in the masses is the mass of CO2 released.
What would happen if you put a sample of the yeast and sugar solution in the refrigerator?
yeh i thought it would be cool to do this ... would it be achoholic
Which came first atoms or electrons?
Of the two, electrons. (Protons had to form, perhaps from quarks, before the first atoms could form and the temperature had to be cool enough for protons and electrons to come together to form hydrogen.)
Who was the first solo rap artist to go platinum?
LL Cool J
How much do baby platypuses weigh?
When first hatched, baby platypuses weigh less than a gram.
How do you determine the organic content of a soil sample?
The best way to determine the organic content of a soil sample is the following: 1. First weigh the lab vessel that you will be putting your sample in and write it down. 2. Scoop in 5 g of the sample into the vessel then weigh it again. 3. Subtract the weight of the vessel by the weight you got in #2. This is your starting weight. 4. After adjusting the muffler furnace to 360 C, put the soil sample you have measured out that is in the lab container in the furnace for two hours. 5. After two hours, put on heat resistant gloves and take out the sample to allow it to cool. It will be very hot, much too hot to handle at the moment. 6. When it is cool, weigh the sample again, and just like in #3, subtract the weight of the vessel to this sample weight and you will get the weight of the sample without the weight of the organic matter. 7. Now divide the weight of the of the soil without the organic matter by the starting weight (which should be 5 g), then multiply by 100. This will give you the amount of soil in the sample. Now subtract by 100 from this amount and you will get the amount of organic matter in the soil. For example, If the end weight is 4.7g, then 4.7/5.0 = 0.94, which means that 0.94 x 100= 94%. Therefore, 100-94 = 6% of the soil sample is composed of organic matter.
What are the two methods to cool down substances?
- place a sample in a refrigerator- place a sample in liquid nitrogen
Why do sample should be keep in dark place for 30minutes in determination of iodine value?
to avoid the light go through in the sample and keep the sample cool also.
How much ice water will it take to cool the sample to 20 degrees celsius?
That would depend on the mass of the sample, its temperature, and what the sample is made of.
How much does a 100 dollar bill weigh?
cool it weigh 100kg ha ha ha
Why has North Carolina been called natures sample case?
cause its cool
Why beethoven's symphony is kept as default sample music in windows?
because it is cool
Why that you should cool first the inculating loop or needle before using?
"because otherwise you will kill the bacteria from the heat, and you may also melt the agar jelly that you are innoculating the bacterium onto."
From the thermal decomposition of copper carbonate how can you use conservation of mass to measure the amount of carbon dioxide produced?
Before thermal decomposition, weigh the mass. Thermally decompose. Allow to cool Re-weigh. The difference in the masses is the mass of CO2 released.
What is the sodium content in asparagus?
a lot!! soak it first for about 2 hours in cool water before cooking
What song did LL Cool J sample on Jack the Ripper?
"Ashleys Roachclip" - by the Soul Searchers
