What is the meniscus of water in a test tube?
A meniscus is what happens when you put a liquid into a container. When you put water in a beaker or test tube, you see a curved surface. With most liquids, the attractive force between the liquid and the container is greater than the attraction between the individual liquid molecules.
Why meniscus is not formed in beaker?
The molecules of the wall of the beaker are attracted by water molecules. Since water molecules want to hang together, other water molecules hold on to it when the molecules contact the surface, shape the meniscus. And because the water molecules hang together.
What is a meniscus and why is it important for measuring liquids?
A meniscus occurs because of surface tension in the liquid and must be read at eye level. For a concave meniscus, the correct volume will be read at the bottom of the curve. Reading a meniscus properly is important for lab safety, since mixing incorrect amounts of materials can be dangerous.
Why should you read volumes at the bottom of a meniscus?
The location of the mark on the glass is where the bottom of the meniscus should be in order to have the “true” volume be what’s marked. So by measuring from the bottom of the meniscus, you’re synchronizing your measurement procedure with the procedure of the people who originally calibrated the markings on the glass.
What liquids have a convex meniscus?
This occurs with water and a glass tube. A convex meniscus occurs when the molecules have a stronger attraction to each other than to the container, as with mercury and glass. A flat meniscus occurs with water in some types of plastic tubes; tubes made out of material that water does not stick to.
Which meniscus should be read for colored liquids?
During lab experiments especially in chemistry, we are always told to take a reading at bottom of the meniscus for colourless liquids and the upper meniscus of coloured liquids.
Will you read upper or lower meniscus of KMnO4 solution in burette?
(v) Repeat the titration till three concordant readings are obtained. Since the solution of KMnO4 is of dark colour, the upper meniscus should be considered for noting the burette readings.
What is a meniscus pipette?
The meniscus is the curve seen at the top of a liquid in response to its container. Most liquids, including water, present a concave meniscus. A convex meniscus (sometimes called a “backwards” meniscus) is produced when the molecules of the liquid are more strongly attracted to each other than to the container.
What is acid Hematin method?
What is principle of acid hematin method of hemoglobin estimation? Blood is mixed with an acid solution so that hemoglobin is converted to brown-colored acid hematin. This is then diluted with water till the brown color. matches that of the brown glass standard. The hemoglobin value is read directly from the scale.
How is acid Hematin formed?
This pigment is produced by acid acting upon hemoglobin and is known as formalin pigment or acid hematin. These parasites disintegrate erythrocytes in an unknown manner, and liberate an acid hematin-like pigment which is phagocytized by the reticuloendothelial system.
Which is the Colour of acid Haematin?
brown
Which is the quickest method of Hb estimation?
Direct cyanmethemoglobin method has been the gold standard for hemoglobin estimation but other methods like hemoglobin color scale, Sahli technique, Lovibond-Drabkin technique, Tallqvist technique, copper-sulfate method, HemoCue and automated haematology analyzers are also available.
What is Sahli method?
Sahli’s method is a way to determine the hemoglobin content in the blood. The device contains hemoglobin tube, pipette, stirrer, and a comparator. Hydrochloric acid present in the device converts the hemoglobin into hematin acid which is then diluted so that the diluted hematin acid colour mathes with the comparator.
What is the normal range of HB?
The normal range for hemoglobin is: For men, 13.5 to 17.5 grams per deciliter. For women, 12.0 to 15.5 grams per deciliter.
What are the similarities and differences between chlorophyll and hemoglobin?
The main difference is that hemoglobin is built around iron (Fe), where as chlorophyll is built around magnesium, (Mg). The primary function for hemoglobin is to transport oxygen from the lungs to other parts of the body. Hemoglobin is composed of four elements- carbon, hydrogen, oxygen and nitrogen.
Which metal is present in chlorophyll 11?
Magnesium
Which metal is present in Haemoglobin?
heme group