Chemistry Questions

Mg(NO3)2 is Magnesium nitrate.

In the case of Mg(NO3)2, the metal in the compound is magnesium (Mg), and the non-metal here is called the nitrate ion (NO3). This makes the name of the compound simply magnesium nitrate.

Henry's Law tells that the solubility of a gas is directly proportional to the partial pressure of the gas above the solvent. Hence under high pressure, more gas is dissolved.

Also that Henry's Law involves a constant which is temperature-dependent. Under high temperatures, less gas is dissolved whereas under low temperatures, more gas is dissolved.

For Example ::  

You can think of a can of soda. The contents are under pressure and if you shake the can before opening, the soda fizzes out all over as you open it. So the higher the pressure, the more gas or more CO2 can be dissolved in the drink.

Eliminate choices 1 and 2. Now focus on the temperature. Soda goes flat (loses carbonation or gas) as it warms up. Soda is usually served cold because more of the carbonation or CO2 stays in the drink when the soda is cold.

Hence, in high pressure and low temperature conditions gases are most soluble in water.

Yes, all the given statements are NOT true about electrons and atomic orbitals.

True statements are ::

An orbital can contain a maximum of two electrons.

An atom’s lowest energy level has only one orbital.

An electron has different amount of energies in all orbitals.

The two main components of air are nitrogen and oxygen. They are seperated by the fractional distillation of liquid air. Liquefied air contains liquid nitrogen and liquid oxygen. Liquid nitrogen with the lower boiling point more readily evaporates than the less volatile liquid oxygen. 

A pure substance can be defined as any single type of material that has not been contaminated by another substance. In chemistry, a pure substance has a definite composition. It can be a compound or an element. A pure substance is considered to be a material that consists of one type of "building block" of matter.

Examples of pure substances include tin, sulfur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) and baking soda (sodium bicarbonate).

Tin, sulfur, and diamond are examples of pure substances which are chemical elements. All elements are pure substances.

Water, sugar, salt and baking soda are pure substances which are chemical compounds. Chemical compounds also are pure substances

While moving from left to right in periodic table basic character of oxide of elements will decrease.

  ∴→Increasing basic strengthAl2O3<MgO<Na2O 

and while descending in the group basic character of corresponding oxides increases. 

 ∴→Increasing basic strengthNa2O<K2O

∴ Correct Order is Al2O3 < MgO <Na2O <K2O