Give the common name for the following compound CH32CH CH2 - Br

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: 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: Polymers are complex molecules composed of random sequences of atoms

Explanation:

Polymers are complex molecules composed of random sequences of atoms is the only statement which is not true regarding 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: 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.

Correct Answer: Oxygen

Explanation:

Oxygen is the final electron acceptor of cellular respiration.

Correct Answer: NaCl (Aq)

Explanation:

Mixtures are combination of two or more substances physically which can be separated in to the original.

Matter can be breakdown into two categories. 

1) Pure substances 

2) Mixtures

 

Here in the given options, options A, B, C are pure substances as they are indicated as S & L in brackets. Option D) is an aqueous solution, that can be dissolved in water.

Correct Answer: Sr

Explanation:

We know that, elements in the same group of the periodic table have similar characteristics. Here magnesium and strontium are the same 2nd group elements and have same behavior. 

Therefore, strontium behaves same as magnesium.