Solution Examples in Chemistry

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Solution.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.

Concept Recap

A homogeneous mixture formed when one or more solutes are completely dissolved in a solvent at the molecular level, resulting in a uniform composition throughout.

One substance completely mixed into another—you can't see separate parts.

Read the full concept explanation →

How to Use These Examples

Read the first worked example with the solution open so the structure is clear.
Try the practice problems before revealing each solution.
Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Solution starts by identifying solute, solvent, amount, volume, and the concentration unit.

Common stuck point: Students often know a formula related to solution but skip the recognition step: Am I tracking solute, solvent, total solution, concentration, dissolving, or dilution rather than just naming a mixture? That leads to a correct-looking substitution attached to the wrong chemical model.

Sense of Study hint: Ask: Am I tracking solute, solvent, total solution, concentration, dissolving, or dilution rather than just naming a mixture?

Worked Examples

Example 1

easy

Define a solution and identify its two main components. Explain what makes a solution different from other types of mixtures.

Answer

\text{Solution = solute + solvent (homogeneous, transparent, stable)}

First step

A solution is a homogeneous mixture where one substance (the solute) is uniformly dissolved in another (the solvent).

Full solution

2
The solute is the substance present in smaller amount; the solvent is present in larger amount and does the dissolving.
3
Unlike suspensions or colloids, solutions are transparent (do not scatter light), do not settle over time, and cannot be separated by filtration.

Solutions are the most common type of homogeneous mixture. They can exist in all states: solid solutions (alloys like brass), liquid solutions (salt water), and gaseous solutions (air).

Example 2

medium

Describe the differences among unsaturated, saturated, and supersaturated solutions. How can you experimentally distinguish between them?

Example 3

medium

You dissolve 20 g of salt in 480 g of water. Find the mass percent concentration.

Example 4

medium

How many grams of

\text{NaCl}

(

M = 58.44\,\text{g/mol}

) are needed to prepare

250\,\text{mL}

of a

0.40\,\text{M}

solution?

Example 5

medium

Convert a

5.0\%

(w/v) glucose solution to molarity. (

M(\text{glucose}) = 180.16\,\text{g/mol}

)

Example 6

medium

Explain why heating typically increases the solubility of most solids in water but decreases the solubility of gases.

Example 7

hard

How would you prepare

500\,\text{mL}

0.100\,\text{M}

\text{H}_2\text{SO}_4

from a

1.00\,\text{M}

stock?

Example 8

challenge

Design a procedure to determine the concentration of an unknown NaOH solution using a

0.100\,\text{M}

HCl standard and an acid–base indicator. Then compute the NaOH concentration if

25.00\,\text{mL}

of NaOH required

18.75\,\text{mL}

0.100\,\text{M}

HCl to reach the endpoint.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

medium

A student dissolves

35

g of NaCl in

100

g of water at

25°\text{C}

. The solubility of NaCl at

25°\text{C}

36\,\text{g per 100 g water}

. Is this solution saturated, unsaturated, or supersaturated?

Example 2

hard

A student prepares a solution by dissolving

80

g of

\text{KNO}_3

100

g of water at

60°\text{C}

(solubility =

106\,\text{g/100 g}

), then slowly cools it to

20°\text{C}

(solubility =

31\,\text{g/100 g}

). How many grams of

easy

0.5

mol of solute is dissolved in enough water to make

1.0

L of solution. What is the molarity?

Example 27

easy

Is a solution always a liquid? Answer yes or no.

Example 28

medium

Calculate the molarity when

4.00

g of

\text{NaOH}

(

M = 40.00\,\text{g/mol}

) is dissolved in enough water to make

500\,\text{mL}

of solution.

Example 29

medium

Using

M_1 V_1 = M_2 V_2

: what volume of

6.0\,\text{M}

HCl is needed to make

250\,\text{mL}

0.50\,\text{M}

HCl?

Example 30

medium

Solubility of

\text{KCl}

20°\text{C}

34\,\text{g}

per

100

g water. A student dissolves

20

\text{KCl}

100

g water at

20°\text{C}

. Is the solution saturated, unsaturated, or supersaturated?

Example 31

medium

Calculate the molality of a solution made by dissolving

0.20

mol of solute in

500

g of solvent.

Example 32

medium

What is the mole fraction of ethanol when

46

g ethanol (

M = 46\,\text{g/mol}

) is dissolved in

54

g water (

M = 18\,\text{g/mol}

Example 33

medium

What mass of

\text{KNO}_3

is dissolved in

250

g of a solution that is

20\%

\text{KNO}_3

by mass?

Example 34

hard

50.0

mL of

0.300\,\text{M}

NaCl is mixed with

150.0

mL of

0.100\,\text{M}

NaCl. Find the final concentration of

\text{Cl}^-

. Assume volumes are additive.

Example 35

hard

Calculate the pH of a

0.010\,\text{M}

HCl solution.

Example 36

hard

\text{Ca(OH)}_2

solution has

[\text{OH}^-] = 1.0 \times 10^{-3}\,\text{M}

. Find the pH at

25°\text{C}

Example 37

hard

A solution is labeled

35\%

HCl by mass with a density of

1.18\,\text{g/mL}

. What is its molarity? (

M(\text{HCl}) = 36.46\,\text{g/mol}

)

Example 38

hard

Solubility of

\text{NaNO}_3

70°\text{C}

130\,\text{g}/100\,\text{g}

water; at

20°\text{C}

it is

88\,\text{g}/100\,\text{g}

water. If

130

g of

\text{NaNO}_3

is dissolved in

100

g water at

70°\text{C}

and cooled to

20°\text{C}

, how much

\text{NaNO}_3

crystallizes out?

Example 39

challenge

Mix

25.0\,\text{mL}

0.200\,\text{M}

HCl with

50.0\,\text{mL}

0.100\,\text{M}

NaOH. What is the pH of the resulting solution? Assume volumes are additive.

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Related Concepts

Mixture Solute Solvent Concentration Solubility

Background Knowledge

These ideas may be useful before you work through the harder examples.

mixture