What is a meniscus in a test tube?
What is a meniscus 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 liquids in a test tube form a meniscus?
Formation of a Meniscus When liquid water is confined in a tube, its surface (meniscus) has a concave shape because water wets the surface and creeps up the side. Mercury does not wet glass – the cohesive forces within the drops are stronger than the adhesive forces between the drops and glass.
What is meniscus in measuring cylinder?
A concave surface of a liquid resulting from surface tension. The bottom of the meniscus is used to measure the volume of a liquid in apparatus such as a graduated cylinder.
Do you read the top or bottom of the meniscus?
The key to getting an accurate reading, is to measure the center of the meniscus whether it be concave or convex. E.g. with a concave meniscus, measure the bottom of the meniscus and for convex meniscus, take the reading from the top of the meniscus.
What is the difference between concave and convex meniscus?
A concave meniscus, which is what you normally will see, occurs when the molecules of the liquid are attracted to those of the container. A convex meniscus occurs when the molecules have a stronger attraction to each other than to the container, as with mercury and glass.
What part of the meniscus do you read?
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. For a convex meniscus, the opposite is true and the correct reading will be at the top of the curve.
Why does a meniscus form?
Fluid molecules are attracted to the molecules in the wall of the glass beaker and since fluid molecules like to stick together, when the molecules touching the fluid cling to it, other molecules of fluid cling to the molecules touching the glass, which forms a meniscus.
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.
Why is Haemin test done?
Haemin crystals are used in medico-legal practices to distinguish fresh or dried blood stains from other red-coloured stains. The shape of haemin crystals varies in different species and thus, blood stains of human can be confirmed.
Why only HCL is used in Sahli’s method?
Answer. Concentrated acid if used in Sahli’s method gives always the same colour for different hemoglobin concentrations, hence it can’t be used for hemoglobin estimation.
Which metal is present in Haemoglobin?
heme group
What is the function of myoglobin?
Myoglobin facilitates oxygen diffusion. Myoglobin desaturates at the onset of muscle activity, which increases oxygen’s diffusion gradient from the capillaries to the cytoplasm. Myoglobin has also been shown to have enzymatic functions. It is necessary for the decomposition of bioactive nitric oxide to nitrate.
What happens if hemoglobin is high?
High hemoglobin levels It causes the body to make too many red blood cells, causing the blood to be thicker than usual. This can lead to clots, heart attacks, and strokes. It is a serious lifelong condition that can be fatal if it is not treated.
Can high hemoglobin cause high blood pressure?
It has been hypothesized that an increased hemoglobin level elevates blood pressure. The present study investigated the association between hemoglobin level and systolic blood pressure and diastolic blood pressure in healthy persons.