Chemistry Solutions Concentration Flashcards

Questions and Answers

What is concentration?

A measurement of the amount of solute that is dissolved in a given quantity of solvent; usually expressed as mol/L.

What is a dilute solution?

A solution that contains a small amount of solute.

What is a concentrated solution?

A solution containing a large amount of solute.

What does molarity (M) represent?

The concentration of solute in a solution expressed as the number of moles of solute dissolved in 1 liter of solution. Signup and view all the answers

How do you calculate the molarity of a solution?

Divide the moles of solute by the volume of the solution. Signup and view all the answers

What effect does dilution have on the total moles of solute in a solution?

Diluting a solution reduces the number of moles of solute per unit volume, but the total number of moles of solute in solution does not change. Signup and view all the answers

What are two ways to express the percent concentration of a solution?

As the ratio of the volume of the solute to the volume of the solution or as the ratio of the mass of the solute to the mass of the solution. Signup and view all the answers

The terms concentrated and dilute are only qualitative descriptions of the amount of a solute in solution.

True Signup and view all the answers

What is the equation for molarity?

Molarity (M) = moles of solute/liters of solution Signup and view all the answers

What is the concentration of the saline solution that contains 0.90 g NaCl in exactly 100 mL of solution?

0.15 mol/L or 0.15 M Signup and view all the answers

What is the molar mass of NaCl?

58.5 g/mol Signup and view all the answers

How do you convert the concentration from g/100 mL to mol/L?

The sequence is g/100 mL → mol/100 mL → mol/L. Signup and view all the answers

What is the calculation for solution concentration when you have 0.90 g of NaCl in 100 mL?

(0.90 g NaCl/100 mL) x (1 mol NaCl/58.5 g NaCl) x (1000 mL/1 L) Signup and view all the answers

Moles of solute before dilution equal the moles of solute after dilution.

True Signup and view all the answers

What is the formula for calculating moles of solute?

Moles of solute = molarity (M) × liters of solution (V) Signup and view all the answers

How do you calculate percent by volume?

(volume of solute/solution volume) x 100% Signup and view all the answers

How do you calculate percent by mass?

(mass of solute/mass of solution) x 100% Signup and view all the answers

Study Notes

Concentration of Solutions

Concentration measures the quantity of solute in a solvent, typically expressed as moles per liter (mol/L).
A dilute solution has a low concentration of solute, while a concentrated solution has a high concentration of solute.
Molarity (M) is defined as the number of moles of solute per liter of solution.
To calculate molarity, divide moles of solute by the solution volume in liters.
Dilution decreases the solution's concentration (moles per volume), but the total moles of solute remain unchanged.
Percent concentration can be expressed as:
- Volume ratio of solute to total solution volume.
- Mass ratio of solute to total solution mass.
Terms "concentrated" and "dilute" are qualitative descriptors, not quantitative measurements.

Molarity Equation

Molarity (M) formula: M = moles of solute/liters of solution.

Example Calculation

IV saline example: 0.90 g of NaCl in 100 mL of solution.
Known values:
- Concentration: 0.90 g NaCl/100 mL.
- Molar mass of NaCl: 58.5 g/mol.

Calculation Steps

Convert concentration to molarity (mol/L) via the path:
- g/100 mL → mol/100 mL → mol/L.
To find moles of NaCl in 100 mL:
- Use molar mass to convert grams to moles.
- Change volume from mL to L for final molarity calculation.

Final Solution Concentration

Calculation example:
- (0.90 g NaCl/100 mL) x (1 mol/58.5 g) x (1000 mL/1 L) = 0.15 mol/L = 0.15 M.

Moles of Solute in Dilution

The number of moles of solute before dilution equals the number after dilution.
Relationship expressed as: Moles of solute = M₁ × V₁ = M₂ × V₂.

Percent Concentration Definitions

Percent by Volume: (volume of solute/total solution volume) x 100%.
Percent by Mass: (mass of solute/total solution mass) x 100%.

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Description

Test your knowledge of solution concentration terms with these flashcards. Learn key definitions including concentration, dilute, concentrated solutions, and molarity. Perfect for chemistry students looking to reinforce their understanding of solution concepts.