ANS:D - molarity

Molarity (M) is a measure of the concentration of a solute in a solution and is defined as the number of moles of solute dissolved per liter of solution. It is one of the most commonly used methods to express the concentration of a solution in chemistry. Here's a breakdown of how molarity is calculated and used:

1. Formula: Molarity (M) is calculated using the formula: 𝑀=Number of moles of soluteVolume of solution in litersM=Volume of solution in litersNumber of moles of solute​
2. Units: The units for molarity are moles per liter (mol/L) or sometimes written as molarity (M).
3. Interpretation: Molarity represents the amount of solute present in a given volume of solution. For example, a 1 M solution of sodium chloride (NaCl) contains 1 mole of NaCl dissolved in 1 liter of solution. Similarly, a 0.5 M solution of sulfuric acid (H2SO4) contains 0.5 moles of H2SO4 dissolved in 1 liter of solution.
4. Concentration Changes: Changing the amount of solute or solvent changes the molarity of the solution. Adding more solute or removing solvent increases the molarity, while adding more solvent or removing solute decreases the molarity.
5. Dilution: Diluting a solution involves adding more solvent to decrease the concentration of the solute. When diluting a solution, the moles of solute remain constant, but the volume of the solution increases, resulting in a decrease in molarity. The relationship between the initial and final molarity of a solution after dilution is given by the equation: 𝑀1⋅𝑉1=𝑀2⋅𝑉2M1​⋅V1​=M2​⋅V2​ Where:
   • 𝑀1M1​ and 𝑀2M2​ are the initial and final molarity of the solution, respectively,
   • 𝑉1V1​ and 𝑉2V2​ are the initial and final volumes of the solution, respectively.
6. Uses: Molarity is used in various chemical calculations, such as preparing solutions of known concentrations, determining reaction stoichiometry, and calculating reaction rates.

In summary, molarity is a measure of the concentration of a solute in a solution, expressed as the number of moles of solute per liter of solution. It is an important concept in chemistry and is widely used in various laboratory and industrial applications.