Which statement is NOT true about polymers?

Correct Answer: 4 is correct

Explanation:

Van't Hoff factor (i) =  O b s e r v e d C o l l i g a t i v e P r o p e r t y N o r m a l C o l l i g a t i v e P r o p e r t y

 

A x B y 1 - ? ? x A + y x ? + y B - x y ?  

 

Total Moles =  1 - ? + x ? + y ? =  1 - ? x + y - 1

 

i = 1 + ? x + y - 1 1

 

? ? = i - 1 x + y - 1

Correct Answer: Methanol (CH3OH)

Explanation:

Chemical Compounds with stronger intermolecular forces have higher boiling points.

 

The order of strengths of intermolecular forces is:

 London dispersion < dipole-dipole < H-bonding

 

${\text{Methane (CH}}_{\mathrm{4)}}$ ? London dispersion forces

${\text{Dimethyl ether (CH}}_3{\text{OCH}}_{\mathrm{3)}}$ ? dipole-dipole attractions

${\text{Methanol (CH}}_3\text{OH)}$ ? hydrogen bonding

Therefore, ${\text{Methanol -}}^{}$${\text{CH}}_3\text{OH}$$\text{with H-Bonding have highest Boiling Point among the given chemical compounds.}$

Correct Answer: Amino acids

Explanation:

Proteins are long chains of Amino acids. That is in brief, Amino acids are the monomers of Proteins. Amino acids are compounds which contain both an amino group and a carboxylic group. Proteins are made up of 20 essential amino acids.

Monomer means a small molecule of an organic substance i.e, building block in general.

 

Correct Answer: Polarity :: The polarity of a molecule defines its other physical properties such as melting point, boiling point, surface tension, vapor pressure etc Simply, polarity occurs when the electron distribution in a molecule is asymmetric This results in a net dipole moment in the molecule One end of the molecule is charged negative while the other gets a positive charge The polarization of a molecule greatly depends on the shape of the molecule A diatomic molecule like HF mentioned above has no issue of shape The net dipole moment is only due to the uneven distribution of electrons between the two atoms However, when there are more than two atoms involved in making a bond, there are many complexities The water molecule is of bent shape Therefore, when the two pair of electrons shared by oxygen with two hydrogen atoms is pulled towards oxygen, the net dipole moment results in the direction of the oxygen atom There is no other force to cancel out the resultant dipole moment Hence, the water molecule is highly polar Ammonia molecule is of a pyramid shape and the electronegative N atom pulls the electrons towards itself The three N-H bonds are not in the same plane; hence the dipole moments created do not get canceled out This makes ammonia a polar molecule However, the dipole moments sometimes get canceled due to the shape of the molecules, making the molecule non-polar Carbon dioxide is such a molecule

Correct Answer: 1 proton only

Explanation:

The nucleus of hydrogen consists of only a single proton.

Its parts are a single negatively-charged electron that circles a single positively-charged nucleus of the hydrogen atom.

The electron is bound to the nucleus by the Coulomb force.

Correct Answer: The number of protons is equal to the number of electrons.

Explanation:

The number of protons is equal to the number of electrons. That is the number of positive charges is equal to the number of negative charges.

Correct Answer: Zn

Explanation:

In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic bonds. Metals are opaque, lustrous elements that are good conductors of heat and electricity. Most metals are malleable and ductile and are, in general, denser than the other elemental substances.

 

Examples of metals are aluminium, copper, iron, tin, gold, lead, silver, titanium, uranium, and zinc.

 

Here Se - Selenium is an element but is not a metal, S - Sulphur is not a metal and I - Iodine is also not a metal.

 

Hence, Zn - Zinc is the only metal in the given options.

Correct Answer: Isobutyl bromide

Correct Answer: Emulsion

Explanation:

Milk is an emulsion of oil in water (o/w).

Emulsion: A suspension of droplets of one liquid in another.

Constituents of milk :

The principal constituents of milk are water, fat, proteins, lactose (milk sugar) and minerals (salts). Milk also contains trace amounts of other substances such as pigments, enzymes, vitamins, phospholipids (substances with fatlike properties), and gases.

Correct Answer: a nonpolar molecule with polar bonds

Explanation:

The four bonds of carbon tetrachloride (CCl4) are polar, but the molecule is nonpolar because the bond polarity is cancelled by the symmetric tetrahedral shape. Hence, making the net dipole as zero and molecule as non-polar.

 

When other atoms substitute for some of the Cl atoms, the symmetry is broken and the molecule becomes polar.