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Chemical Reaction Quiz Part16

  Chemical Reaction Quiz

Science Quiz by
This Chemical Reaction Quiz part16 is based on chemical reactions.

1. Chemical reaction always gives-

A change of state
A different substance
All of the above

2. From given below, 4-balanced chemical equations, which is example of combustion reaction-

2Mg + O2 → 2MgO
2N2 + 3H2 → 2NH3
CaO + H2O → Ca(OH)2
2Na + Cl2 → 2NaCl
2CH4 + 4O2 → 2CO2 + 4H2O

3. To balance a chemical equation, you should need to change-

Chemical Formulas
Direction of the arrow

4. In chemistry, if you try to balance a chemical equation by changing its subscripts, than you change the-

Atomic number
Atomic Mass
Mass of the reactants
Number of molecules of product
Identity of the compound

5. From given below, 4-balanced chemical equations, which is example of double displacement reaction-

NH4Cl → NH3 + HCl
Cd(NO3)2 + Na2S → CdS + 2NaNO3
2Mg + O2 → 2MgO
2H2O2 → 2H2O + O2
2N2 + 3H2 → 2NH3

6. Chemical Reaction, KClO3 → KCl + O2 is a-

Synthesis Reaction
Decomposition Reaction
Combustion Reaction
Single Displacement Reaction
Double Displacement Reaction

7. Which scientist first determined that the masses of the reactants and the products in a chemical reaction must be same-


8. Combination reactions (also known as Synthesis Reaction) always-

Involve an element and an ionic compound
Require oxygen gas
Use only one reactant
Form only one product
form only two product

9. In a chemical reaction, the arrow means-

A reaction is happening
The equation is balanced
The products flow into reactants
The two sides are equal
All of the above

10. In a decomposition reaction-

Energy in the form of light or heat is often released
Reactants are commonly two ionic compounds in the aqueous solution
one of the reactant is generally water
Form only one product
Reactants in the chemical reaction are usually a metal and a nonmetal

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Amino Acids

Amino Acids

Definition of Amino Acid

Amino acid is a simple organic compound that contains a carboxyl (—COOH) and an amino (—NH2) group.

What are Amino Acids?

Amino acids are organic compounds containing carboxyl (—COOH) and amino (—NH2) functional group with side chain, this side chain is specific to amino acid. Carbon, Hydrogen, Oxygen and Nitrogen are some important element which present in amino acids. Some other elements may also present in side chain of some amino acids.

Importance of Amino Acids

As we all know that our body contains large amount of proteins also these proteins play important role in biological processes happening within human body. Amino acids are building blocks of these proteins means proteins contain amino acids.
Amino acids play key role in many body functions like cell structure, storage and transport of nutrients, proper functioning of organs, proper functioning of glands, proper functioning of arteries, proper functioning of tendons, healing of wounds, repairing tissues, removal of metabolic waste etc.

Amino Acids

There are so many amino acids present in nature but gene codes only 20 amino acid. Essential amino acids are type of amino acid which can not produced by human body so they are needed in dietary food. Two amino acids combines by a peptide bond to form dipeptide.
peptide bond
And amino acids further added to grow chain of peptides to form poly-peptide or protein.

Areas of use of Amino Acids

1. Anti-aging

Supply of amino acids to the body provides repair treatment means nourish human skin, nails and hair result in delay aging process naturally. Supply of amino acids strengthens connective tissue to keep our skin smooth, shine, glowing and elastic. Creatine play very important role to keep skin healthy and this creatine is made up of amino acids like Arginine and Methionine. Glutamine amino acid is responsible to regulate acid-base balance as a result it supports healthy skin. Carnitine is a di-peptide containing two essential amino acids lysine and Methionine. Carnitine helps in burning fat to produce energy so also known as fat burner so also added in fitness and wellness program.

2. Arthritis

Amino acid Methionine helps in cartilage formation, also Methionine is essential amino acid so do not get produced within human body but need to be provided from outside i.e. from diet or food. Methionine also donates sulphur which helps in joint cartilage creation. Along with amino acids vitamins and minerals are also required for healthy joints.

3. Cholesterol

Arginine amino acid helps in lowering the cholesterol level.

4. Diabetes

In diabetes person’s blood sugar level get high than normal level due to many reasons like pancreas do not produce enough insulin, insulin resistance etc. Amino acid Arginine help in reducing insulin resistance by increasing sensitivity of our body cells toward insulin so insulin get easily absorbed.

5. Fat Burning

Goal of weight loss is achieved by fat burning. Human growth hormone is an important fat burning hormone and amino acids Arginine, Glutamine and Methionine helps to secrete this hormone.

6. Hair and Nails

Amino acid Methionine prevents hair loss and strengthens nails. Amino acid Glutamine and Arginine increases hair growth.


•    Below pH 2.2 amino acid have net charge of +1 due to the predominant form of amino acid have a neutral carboxylic acid functional group and a positive α-ammonium.
•    Above pH 9.4 amino acid have net charge of -1 due to the predominant form of amino acid have a negative carboxylate and neutral α-amino group.
•    At pH between 2.2 and 9.4 amino acid have net charge of ZERO due to the predominant form of amino acid have both a negative carboxylate and a positive α-ammonium functional group and this molecular state of amino acid is known as a Zwitterion.

Isoelectric Point

 Isoelectric point is a pH at which molecule carry zero net electric charge. In case of amino acids at pH between 2.2 and 9.4 amino acid have net electric charge of ZERO so this range of pH gives Isoelectric Point of Amino Acids as shown in below image.

List of Amino Acids

list of amino acids

Essential Amino Acids

Essential amino acids are amino acids which cannot be synthesized by the human body so these amino acids must be supplied in diet. The nine essential amino acids, which human body cannot synthesize are phenylalanine, Valine, Threonine, Tryptophan, Methionine, Leucine, Isoleucine, Lysine, and Histidine i.e. in one letter for amino acids are as follows- F, V, T, W, M, L, I, K, H.
Six additional amino acids are measured conditionally essential in the human diet. These six amino acids are Arginine, Cysteine, Glycine, Glutamine, Proline, and Tyrosine i.e. in one letter for amino acids are as follows- R, C, G, Q, P, Y.
Five amino acids are not essential in humans because they fully synthesized in the body. These five amino acids are Alanine, Aspartic Acid, Asparagine, Glutamic Acid, and Serine i.e. in one letter for amino acids are as follows- A, D, N, E, S.

List of Essential Amino Acids and Non-Essential Amino Acids

List of Essential Amino Acids and list of Non-Essential Amino Acids

Amino Acid Images



Density of many samples is measured in labs for example in unites states 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'. 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
           ρ = m/V
           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

Instruments used to measure Density

Hydrometer and Thermometer is used to measure the density of liquids.
Hydrometer to measure Density

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

Density (Kg/m3)
At sea level
1027 to 1033
At 20 oC
At 20 oC
Coconut Oil
At 15 oC
Cotton Seed Oil
At 16 oC
Olive Oil
At 15 oC
Sunflower Oil
At 20 oC
Rice Bran Oil
At 20 oC
Groundnut Oil
At 20 oC
Liquid Hydrogen
At about -255 oC
At 0 oC
Fresh Water
At 4 oC
Approx for PVC
Also called Glycerine or Glycerin
Chief ore of Aluminium is Bauxite
Precious stone
Zinc is found in cells throughout the body.
Used since ancient times
Found in the Earth's crust only in chemically combined form
Silvery-white lustrous metal
Very high thermal and electrical conductivity
Highest electrical conductivity, thermal conductivity
Soft, malleable, and heavy metal
Only metallic element that is liquid at room temperature
weakly radioactive because all its isotopes are unstable
Densest naturally occurring element
Densest naturally occurring element

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