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Physical and chemical properties of acetic acid. Science GSEB std 8 to 12.

Acetic acid Physical and Chemical properties

AIM : To study the physical and chemical properties of acetic acid.

THEORY : Acetic acid in an organic acid. It contains carboxylic acid group – COOH. Its chemical reactions are the characteristics of COOH group.

APPARATUS : Three to four test tubes, test tube stand. Acetic Acid, Organic acid, Carbozylic acid, Zinc metal, Vinegar, Sodium Bicarbonate solution, Blue Litmus Paper,

CHEMICALS : Acetic acid, Zinc metal sodium bicarbonate solution and red blue litmus papers.

Acetic acid Properties

Acetic acid Properties procedure

Acetic acid Properties practical

Conclusion :

Uses : 4-6 % solution of acetic acid is called vinegar. It is used for making the food tasty and sour and also used as food preservative.

Micrometer, its construction, reading ITI fitter, and science 11 & 12 students

Micrometer Screw gauge

Micrometer Screw gauge.

Introduction

Micrometer screw gauge is a form of calipers used for measuring small dimensions. Screw gauge in extensively used in the engineering field for obtaining precision measurements. The article describes the principle and main parts of a basic micrometer screw gauge.

Micrometer screw gauge (or micrometer caliper) is an instrument or device for measuring the length of an object which is more precise than a ruler and vernier caliper. It because a micrometer screw gauge has the smallest scale of 0.01 mm. The device is widely used in mechanical engineering for measuring small diameter, thickness, or angles to a high degree of accuracy.

Screw gauge or micrometer screw gauge is a measuring instrument used for precision measurement.

Micrometer Screw Gauge

Frame of Micrometer screw gauge

Anvil

Spindle

Measuring faces

Main scale, Barrel or Sleeve

Thimble, Micrometer Scale

Ratchet stop

Spindle lock nut

Least count of Micrometer

Thimble one round.

1 mm displacement micrometer

Discount calculation

Micromete screw gauge

Objects measurement with Micrometer

Measuring of object with micrometer screw gauge

A screw gauge consists of a “U” shaped metallic structure, which is attached to a hollow cylindrical tube on one end. The hollow tube has a uniformly threaded nut inside it. A long stud with a plane face is fitted into this nut. Exactly on the opposite side of this nut and on the other end of the U shaped frame, a smaller stud with a plane face is also attached. Faces of both the studs are exactly parallel to each other.

This U shaped metallic structure is known as the frame of the micrometer screw gauge. the smaller stud is known as the anvil and the longer one is known as the spindle. the anvil is the fixed part of the device, whereas the spindle moves as and when the head is moved. the frame carries both the anvil and barrel, and is also heavier than the rest of the parts. The object to be measured is held between the anvil and the spindle.

The Barrel or sleeve is connects the frame to the cylindrical tube. It is a non-movable part of the screw gauge and has a scale inscribed over it which is the main scale of the device. Moreover, it also carries the most important part of the micrometer the screw.

The screw is the heart of the micrometer and is located inside the barrel. The screw converts small dimensions into measurable distance using a scale. The thimble or head is the end of the cylindrical tube and is turned to move and adjust the spindle. The thimble carries the vernier or secondary scale. There is one more part called the ratchet which is provided at the end of the tube. The ratchet is kind of limiting device which applies a pressure by slipping at a predetermined torque and thus prevents the spindle from moving further. Some screw gauges also consist of locking devices which holds the scales at a particular position for prevent any kind of error while taking readings.

A micrometer screw gauge also uses two scales –main and secondary scales. The secondary scale is provided on the thimble and is the measurement of the pitch of the screw. This means that the reading on the secondary scale measures the distance moved by the thimble per rotation. The scale on thimble is divided into 100 equal parts and measures hundredths of a millimeter. The thimble scale rotates over the spindle or the main scale. The main scale is a millimeter scale subdivided into equal parts with half a millimeter distance. When the object is to be measured, it is placed in between the anvil and the spindle. Readings from both the scales are taken into account for arriving at the final measurement.

Micrometer screw gauge is a delicate device and thus special care should be taken while handling it. Moreover, it is also important that the micrometer is well calibrated to prevent any kind of error in the final reading.

Precaution Steps

The spindle and anvil are cleaned with a tissue or cloth, so that any dirt present will not be measured.

Watch video to Learn reading of
Micrometer screw gauge reading without the help of tutor. It is very easy to understand.

Micrometer screw gauge:

Rocks, Minerals and Metals, for Standard 8 theory and practical With Understanding drawings.

Science for Standard 8 theory and practical With Understanding drawings.

Rocks, Minral and Metals

Rocks, Minerals and Metals

Rocks are found on the crust of the earth and made up of mineral

SHALE,

LIMESTONE,

SANDSTONE,

FOLDED ROCK FORMATION,

GAS,

OIL,

WATER,

IRON ROCK,

Rocks Minral and Metals

Some are coarse grained as granite. Clay has much fine grains that we cannot see them separately. If you closely examine a piece of granite, you will find that it is made up of a number of substances under a magnifying lens or a microscope. Substances which assemble together to form rocks are called minerals. Minerals are naturally occurring inorganic substances.

Magnifying lens to see sand grade

Tags:- Rocks, Mineral, Metal, Shale, Limestone, Sandstone, Rock_Formation, Gas, Oil, Water, Iron_Rock

The Earth’s Crust

Remainder of the crust consists of mainly six metals

(1) Aluminum (most abundant)

(2) Iron

(3) Calcium

(4) Sodium

(5) Potassium

(6) Magnesium.

Three forth of the earth crust is made just of two non metals.

(1) Oxygen (2) Silicon.

The average thickness of earth crust is 35 km under the continents and 10 km under the oceans.

Earth Crust

Tag:- Aluminum, Iron, Calcium, Sodium, Potassium, Magnesium, Earth’s_Crust

Rocks formation

Meaning:- Word derived from the latin word ‘ignis’ meaning fire. First rock to appear on the earth’s surface.

Formation:- Formed by the cooling and solidification of extremely hot molten material, magma below the earth crust.

This magma pushes its way through earth’s crust with high pressure to form igneous rocks.

Large part of west central part of our country called the Decean Plateau.

Granite is formed when the rising magma solidifies before reaching the surface in the form of coarse grained.

Igneous Rocks

By the deposition fo sediments SEDIMENTS are broken down particles of existing rocks which are deposited layers by layers by flowing water or wind in the sea along with dead plants and animals.

All this are neatly preserved in the sediments.

The process goes on for millions of years and the resultant rocks are called Sedimentary rocks.

Sedimentary rocks contains the relics of plants & animal known as Fossils.

They harden with age.

Thickness of overlaying layers are usually soft.

Sedimentary Rocks

FORMATION :- When igneous or sedimentary rocks are subjected to intense heat, compression or fluid injection the physical & chemical properties changes which results in metamorphic rock

Metamorphic Rocs

Tag:- ignis, Igneous Rocks, Sedimentary Rocks, Metamorphic Rocks, Heat, Pressure, Formation

Minerals

Naturally occuring inorganic substances with specific composition.

Substance which assemble together to form rocks are called Minerals. There are about 2000 distinctive minerals.

A mineral made of atom of a single element or of more than one elements.

It is identified by its physical properties such as colour, lustre, hardness, specific gravity and cleavage.

Types of Mineral

Non-metallic minerals and their uses

Minerals and their uses

Uses of Minerals

Some common ores :-

Some Common Ores

Tag: - Galena, Magnetite, Pyrite, Oxide, Sulphide, Aluminium, iron, Copper, Lead, Quarz, Feldspur , Mica, Rock salt, Gypsum, Talc, Pitch blend, Monazite.

BLAST FURNACE

Blast furnace and its structure

Blast furnace total height is about 30-40 meters.

FeO + CO ® Fe + CO₂

Iron oxide, limestone & coke

CaCO₃heat CaO + CO₂

CaO + SiO₂ ®CasiO₃

Impurities slag

Fe₂O₃ + C ® 2 Fe₃O₄ + CO

Fe₃O₄ + CO ® 3 FeO + CO₂

Out side portion is made up of steel, and inside portion is lined with fire bricks.

Middle portion of the furnace is known as BOSCH.its width is about 7-8 meters.

Cone & Glass shape

HOT AIR

Waste gas

SLAG

Calcium silicate

MOLTEN IRON

Blast furnace

The concentrated ore along with coke (c) and limestone are added to a blast furnace. Blasts of hot air at about 1900⁰ C are blown into the furnace lined with fire bricks. The coke reduces the ore to metallic iron. The molten iron collects at the bottom of the furnace. Limestone on heating decomposes to calcium oxide and carbon dioxide. Calcium oxide reacts with the sand and forms a slag (calcium silicate.

Pig iron & Wrought iron

Pig iron and Wrought iron

Tag : - Slag, Waste gas, Blast_Furnace, Pig_iron, Wrought_Iron, Molten_iron, Calcium silicate, Iron_oxide

More details view Video Blast Furnace.

Beautiful understanding with animation of how Blast furnace works.

Thursday, June 11, 2026

Physical and chemical properties of acetic acid. Science GSEB std 8 to 12.

Micrometer, its construction, reading ITI fitter, and science 11 & 12 students

Micrometer Screw gauge.

Rocks, Minerals and Metals, for Standard 8 theory and practical With Understanding drawings.