Chemistry Podcast

Showing posts with label CHEMISTRY TERMINOLOGY. Show all posts
Showing posts with label CHEMISTRY TERMINOLOGY. Show all posts

Saturday, 5 February 2022

What is Heat in Science | What is Temperature in Science | How to measure Temperature with Thermometer

What is Heat?

The exchange of energy due to difference in temperature is called heat. But as a noun we can say that the Heat is the quality of being hot or high temperature and to understand easily we can say that feeling of hot or warm is heat.



What is Heat in Science ?

The exchange of energy due to difference in temperature is called heat. We may also explain as, heat is the form of the energy that is moved between two substances at different temperatures. Means if two substances are in contact and one has 200K temperature and other have 100K temperature then the direction of energy flow is from the substance at the higher temperature to the substance of lower temperature. Means in above case heat flows from substance having 200k temperature to substance having 100K temperature.
Heat is a form of energy so heat is measured in units of energy, commonly calories or joules.

What is Temperature?

Temperature is the quantity of hotness or coldness of any substance. Simply we can say that Temperature is the measurement of how much an object is hot or cold.

What is Temperature in Science ?

Temperature is the quantity of hotness or coldness. Also in scientific way, temperature is explained as the average kinetic energy per molecule of a substance. Heat and Temperature (Temp, T) are two different terms and have different meanings so don’t get confuse between them.  Heat is energy while temperature is not energy. Heat is measured in Joules while temperature is measured in Celsius (C), Fahrenheit (F) or Kelvin (K). Symbol used for heat is Q while symbol used for temperature is T. SI unit of heat is Joule while SI unit of temperature is Kelvin.

Heat VS Temperature in Chemistry

Heat is the flow of energy from hot object to cold object while temperature is the measurement of how much an object is hot or cold. Heat is energy while temperature is not energy. Heat is measured in Joules while temperature is measured in Celsius (C), Fahrenheit (F) or Kelvin (K). Symbol used for heat is Q while symbol used for temperature is T. SI unit of heat is Joule while SI unit of temperature is Kelvin.

How to measure Temperature with Thermometer in degree Celsius & Fahrenheit

This video explains- 
How do you measure temperature with a thermometer?
and How do you read a Fahrenheit and Celsius thermometer?
After watching this video on temp., you can easily check temperature with thermometer.


Temperature is the measure of hotness or coldness of an object.
To convert temperatures from Fahrenheit to Celsius, 
use the formula C=(5/9)(F−32) 
and for Celsius to Fahrenheit, use the formula F=(9C/5)+32.

How to convert Temperature from one Unit to Another
By using below temperature conversion calculator, you can convert temperature from degree celsius to degree fahrenheit, degree celsius to kelvin. Similarly, from degree fahrenheit to degree celsius & degree fehrenheit to kelvin. Similarly, from kelvin to degree celsius and kelvin to degree fahrenheit.

Relationship between degree Celsius and degree Fahrenheit

    Use the formula ºC=(5/9)(ºF−32)

Relationship between degree Celsius and degree Kelvin

    Use the formula K = ºC + 273.15

Relationship between kelvin and degree Fahrenheit

   Use the formula K = 5/9 ºF + 459.67

Friday, 4 February 2022

What is Density in Chemistry - Definition, Symbol, SI Units, Formula & Measurement of Density

Definition, Symbol, SI Units, Formula & Measurement of Density

Density is simply mass per unit volume. Density of many samples is measured in labs for example in oil and gas industry. They define density in general way as 'weight per unit volume' although 'weight per unit volume' is not density it is 'Specific Weight' so density is 'mass per unit volume'

Example of Density

Don't worry! we will going to learning density in very simple way, with examples.
Do you ever see a dry WOOD piece floating over water in river or pool? 
Yes, We all see that, Do you think why it floats. Because density of wood 🪵 is lesser than density of water 💧 so piece of 🪵 wood experience upthrust force and float on water 💧. 

Take another example of Iron Metal piece and water. IRON METAL piece has higher density than WATER, so piece of iron metal sink in water.

To understand clearly, we will take another example of 'Sunflower Cooking oil' & 'Water'. When we mix 'Sunflower Cooking oil' & 'Water', after some time oil comes at top and water set below (means separate out). So now question is why this happens? Answer is due to difference in density & nature of water and oil. Oil is nonpolar while water is polar molecule so they don’t interact with each other. 
Density of Sunflower Cooking oil is 919 Kg/m3
Density of Water is 1000 kg/m3

What is Density in Chemistry

In science/chemistry, density of a substance is its mass per unit volume.  Density is also known as "Volumetric Mass Density". 

Generally different materials have different density. Chemical element Osmium (Os having atomic number 76) is naturally occurring densest element. To simplify the comparison of densities of different materials or liquids it is needed to replace density with "relative density" as relative density is dimensionless quantity. Relative Density is also called "Specific Gravity". 

Specific gravity or relative density is the ratio of density of sample material to the density of standard material. Generally water is taken as standard material. If we take water as standard material than if we get relative density of a material is less than '1' means that material floats in water. Water has highest density at 4 °C i.e. 1000Kg/m3.

Density of material depends on the temperature and pressure. Effect of temperature and pressure is very less on solid and liquid but effect of temperature and pressure is very high on gases. If we increase pressure on given material than its volume get decrease that result in increase in density, similarly If we decrease pressure on given material than its volume get increase that result in decrease in density. 

And in case of temperature, if we increase temperature on given material than its volume get increase that result in decrease in density, similarly if we decrease temperature on given material than its volume get decrease that result in increase in density. 

But their are some exceptions which do not follow these rules, one of them is water means when temperature of water decreases than it makes solid ice which float on liquid water as ice have less density than liquid water i.e. Density of ice is 916.7 Kg/m3 at 0 °C, and water has a density of 999.8 Kg/m³ at 0 °C.

Definition of Density

                           Density of a material is defined as its mass per unit volume.

Symbol of Density

                             Symbol of density is 'ρ' or 'D' and pronounces as 'rho'.

Formula of Density

                             Density = Mass/Volume
or,
           ρ = m/V
where,
           ρ is density, m is mass and V is volume.
  • When numerator (mass) is much larger than denominator (volume) in density formula, that shows the given substance has higher density, but when denominator (volume) is much larger than the numerator (mass), that shows the given substance has lower density.

SI Unit of Density

                             SI Unit of Density is Kg/m3 or g/cm3

Density Calculator

    Density is calculated by dividing mass by volume. Density is measured as units of mass/volume, often g/cm3, g/Kg3 or g/mL. Just enter value of mass and volume to get density.

Instruments used to measure Density

Weighing balance, Scale, Hydrometer and Thermometer are some instruments used to measure the density of solids & liquids.
Measurement

How to Measure Density of a Solid

Just watch below video to learn how to measure density of a solid.
    


Hydrometer to measure Density
Hydrometer


Hydrometer dip in mineral oil and engine oil to measure the Density of these samples
Hydrometer dip in mineral oil and engine oil to measure the Density of these samples


Density Chart

Material
Density (Kg/m3)
Remark
Air
1.2
At sea level
Milk
1027 to 1033
At 20 oC
Honey
1420
At 20 oC
Coconut Oil
925
At 15 oC
Cotton Seed Oil
926
At 16 oC
Olive Oil
918
At 15 oC
Sunflower Oil
919
At 20 oC
Rice Bran Oil
918
At 20 oC
Groundnut Oil
913
At 20 oC
Liquid Hydrogen
70
At about -255 oC
Ice
916.7
At 0 oC
Fresh Water
1000
At 4 oC
Plastics
1175
Approx for PVC
Glycerol
1261
Also called Glycerine or Glycerin
Aluminium
2700
Chief ore of Aluminium is Bauxite
Diamond
3500
Precious stone
Zinc
7000
Zinc is found in cells throughout the body.
Iron
7870
Used since ancient times
Cobalt
8900
Found in the Earth's crust only in chemically combined form
Nickel
8900
Silvery-white lustrous metal
copper
8940
Very high thermal and electrical conductivity
Silver
10500
Highest electrical conductivity, thermal conductivity
Lead
11340
Soft, malleable, and heavy metal
Mercury
13546
Only metallic element that is liquid at room temperature
Uranium
18800
weakly radioactive because all its isotopes are unstable
Iridium
22420
Densest naturally occurring element
Osmium
22570
Densest naturally occurring element

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