Answer:
a) Ka= 7.1 × 10⁻⁴; This is a weak acid because the acid is not completely dissociated in solution.
Explanation:
Step 1: Write the dissociation reaction for nitrous acid
HNO₂(aq) ⇄ H⁺(aq) and NO₂⁻(aq)
Step 2: Calculate the acid dissociation constant
Ka = [H⁺] × [NO₂⁻] / [HNO₂]
Ka = 0.022 × 0.022 / 0.68
Ka = 7.1 × 10⁻⁴
Step 3: Determine the strength of the acid
Since Ka is very small, nitrous acid is a weak acid, not completely dissociated in solution.
According to Henry's law, solubility of solution is directly proportional to partial pressure thus,

Solubility at pressure 3.08 atm is 72.5/100, solubility at pressure 8 atm should be calculated.
Putting the values in equation:

On rearranging,

Therefore, solubility will be 1.88 mg of
gas in 1 g of water or, 188 mg of tex]N_{2}[/tex] gas in 100 g of water.
Answer:
The answer is carbon cycle.
Explanation:
The carbon cycle is an important process for living organisms. As plants prepare their food through photosynthesis and is also an important source of fossil fuels for human activities.
Therefore carbon atoms are regenerated again and again in the carbon cycle process. This recycling process takes place between livings and nonliving things in the environment and also within the earth biosphere.
Abundance supply of carbon is necessary to carry out the biological processes. The entire carbon cycle is actually made up of sourced and sinks elements.
I think it's Sodium Sulfide, because Na2S contains one Sodium and two Sulfur. Plus Sulfide<span> is used to describe any of three types of chemical compounds that contain sulfur.</span>
Answer:
The metal cube lattice is made of only one kind of atom.
Explanation:
As we know that metallic crystals are made up of only one kind of element. A metal crystal is actually a huge sea of positive charges embedded in the layers of negative charges (electrons). The whole crystal is made up of same kind of atoms, e.g crystals of gold, crystals of iron.
If we talk about structure of metallic crystal, it can be body centered cubic, simple cubic, hexagonal or close cubic packing.
Now, coming towards the ionic crystals, we know that they are basically the crystals of ionic compounds like sodium chloride or cesium chloride. These crystals are formed due to ionic bonding between two or more than two kinds of elements/atoms. It is not possible for an ionic crystal to be composed of only one kind of atom. As far as structure is concerned, they can have different structure based on bonding between atoms in an ionic compound, e.g NaCl has octahedral geometry.
Therefore, it is very evident that best option is A.