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Suggest a test chemical that can be added to waste water to precipitate lead II ions show a chemical equation for the formation of the precipitate?
Put a little hydrochloric acid in the water sample. 2HCl + Pb -> H2 + PbCl2. Lead chloride is insoluble and its density is much higher than that of water. You can then perform a test on the precipitate to determine the ratio of lead chloride to silver chloride in your precipitate.
What is the only sure evidence for a chemical reaction?
The only sure evidence for a chemical reaction is the formation of new substances with different properties from the original reactants. This can be observed through changes in color, odor, temperature, or the production of a precipitate or gas.
In lead acetate test what element in the amino acid is detected to be present in this test?
The lead acetate test is used to detect the presence of the sulfhydryl (thiol) group in amino acids, particularly cysteine. When lead acetate solution is added to a sample containing a sulfhydryl group, a black precipitate of lead sulfide forms, indicating a positive test for the presence of sulfhydryl groups.
What is the name of chemical test for oxygen?
The chemical test for oxygen is the glowing splint test. In this test, a glowing splint is extinguished in the presence of oxygen due to its ability to support combustion. If the splint reignites, it indicates the absence of oxygen.
Why the test tube with the bromine test exposed to the sunlight or in the dark?
The bromine test is typically conducted in the dark to prevent light-induced reactions from interfering with the test results. Exposure to sunlight can lead to the formation of unwanted byproducts or inaccurate readings. Conducting the test in the dark ensures that the observed color change in the test tube accurately reflects the presence of the functional group being tested for.
Why does heating a test tube cause colour change?
Heating a test tube may cause a color change because it can initiate a chemical reaction, causing substances in the test tube to change in structure or composition. This can lead to the formation of different colored products or the decomposition of the original substance into products with different colors.
Is heating of ammonium chloride in a test tube a physical or chemical change?
Heating of ammonium chloride in a test tube is a physical change. It undergoes sublimation, where it transitions from a solid directly to a gas without changing its chemical composition.
Is there a chemical or physical change in a pH test?
It is a chemical change.
Is heating a wood splint a chemical or physical change?
Heating a wood splint is a physical change because it does not change the chemical composition of the wood. The heating only affects the physical state of the wood, causing it to undergo a reversible change in temperature and possibly shape.
Which is the correct way to hold a test tube whike heating its unknown chemical?
When heating a test tube with any substance in it, you hold it with a test tube holder, pointed away from you and other people.
Is this paint safe?
There is no sure fire way to test paint for lead via home based chemical compounds. The only way to test for lead is to buy a lead paint test kit.
Why is lassaigne's test dangerous?
Lassaigne's test involves the use of concentrated sulfuric acid and heating, which can lead to potential chemical hazards such as acid burns, release of toxic gases, and potential fire hazards. Incorrect handling or insufficient precautions during the test can lead to serious accidents and injuries. It is important to conduct this test in a well-ventilated laboratory and to wear appropriate personal protective equipment.
Is heating a mixture a chemical or physical change?
Heating a wood splint is a chemical change. If this was done in something like a test tube, you will see many things occur that indicate this. First, you will see a werid kind of smoke, the splint turning into black stuff, and a really bad smell. Well the smoke is CO2 and the black stuff is ash from the burning. Because there is a new substance being made and the identity of the original substance(your splint) has changed, the reaction is chemical.
What was the Rochester test?
The Rochester test was an early self-test for lead poisoning using a chemical reaction between hydrogen sulfide gas and a urine sample which would result in a color change - a black color indicated the presence of lead. It was used in the early 20th century before more sophisticated tests were developed.
Why does colour change after 5 minutes of heating during Benedict's test?
Heating is necessary to transform sugars in enediols which react with Cu(2+).
The indicator in a test tube change colour orange to yellow what process is it?
This change in color indicates a chemical reaction taking place in the test tube. The specific reaction that caused the color change would depend on the substances present in the test tube and their chemical properties.
Is the ability to conduct heat classified as a physical property or a chemical property?
Heat of combustion is a chemical property.
