Question

If you dissolve 2.00 mol KI in 1.00 L of water, will you get a 2.00 M solution? Explain.

Short answer

Yes, dissolving 2.00 mol of KI in 1.00 L of water gives a 2.00 M solution.

Step-by-step solution

- Understanding Molarity

Molarity (M) is defined as the number of moles of solute per liter of solution. It is given by the formula: \( M = \frac{moles \:of\: solute}{volume \:of\: solution \:in \:liters} \).

- Identify the Given Values

From the problem, the number of moles of KI (solute) is 2.00 mol, and the volume of water (solution) is 1.00 L.

- Apply the Molarity Formula

Use the given values in the molarity formula:\( M = \frac{2.00 \: moles}{1.00 \: L} \).

- Calculate the Molarity

Perform the division: \( M = 2.00 \: M \).

- Conclusion

Since the calculated molarity is 2.00 M, dissolving 2.00 mol of KI in 1.00 L of water does indeed give a 2.00 M solution.

Key concepts

Molarity

Molarity is a measure of concentration specifically for solutions. It shows how many moles of a solute are in a liter of solution. Imagine you want to know how packed full your solution is with a particular substance. Molarity tells you exactly that. The formula to calculate molarity is: \[ M = \frac{moles \, of \, solute}{volume \, of \, solution \, in \, liters} \] You need two main ingredients: the amount of solute (in moles) and the volume of the solution (in liters).
This concept is vital in chemistry because it helps predict how reactions will proceed and how much of a substance is needed.

Moles of Solute

The mole is a standard unit in chemistry that quantifies the amount of a substance. One mole contains approximately 6.022 x 10^23 particles (atoms or molecules). When we talk about solute, those particles are what we dissolve in a liquid to make a solution.
For example, dissolving 2.00 moles of KI means you have 2.00 x 6.022 x 10^23 KI particles.
Knowing the number of moles helps us calculate molarity and understand the reaction potential of the solution.

Solution Volume

Solution volume refers to the total amount of space that the entire solution (solute + solvent) occupies. It's usually measured in liters (L). This volume must include the dissolved substance and the liquid it’s dissolved in.
In the given problem, the solution volume is 1.00 L.
It is essential to measure it accurately because even slight changes can significantly affect the molarity. Accurate volume measurement ensures precise calculations, which is crucial for preparing consistent and reliable solutions in experiments.

Concentration

Concentration expresses how much of a solute is present in a given quantity of solvent or solution. There are various ways to express concentration, but molarity is one of the most common. It’s particularly useful for chemical reactions because it tells you how much reactive substance you have in a specific volume.
Too much or too little concentration can alter reaction rates and outcomes. In the given problem, a concentration of 2.00 M means you have 2.00 moles of KI in every liter of solution.
Understanding concentration is critical for tasks like diluting a solution or mixing reagents in the right proportions to ensure the desired reaction and results.