Solute Examples: 46 Problems with Answers

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

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

Concept Recap

The substance that is dissolved in a solution, typically present in a smaller amount than the solvent.

The thing that 'disappears' when you dissolve it — like sugar dissolving in tea. The sugar is the solute.

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: Solute asks what the sample is, what property is being used, and whether a new substance is formed.

Common stuck point: Students often know a formula related to solute but skip the recognition step: Am I classifying matter or using properties, state, particle behavior, or mixture evidence to describe a sample? That leads to a correct-looking substitution attached to the wrong chemical model.

Sense of Study hint: Ask: Am I classifying matter or using properties, state, particle behavior, or mixture evidence to describe a sample?

Worked Examples

Example 1

easy

In a solution of sugar dissolved in water, identify the solute and explain its role.

Answer

Solute: sugar (the dissolved substance)

First step

The solute is sugar — it is the substance being dissolved.

Full solution

2
The solute is present in a smaller amount and is dispersed uniformly throughout the solvent.
3
The sugar molecules separate and become surrounded by water molecules.

The solute is the minor component of a solution. It can be a solid, liquid, or gas dissolved in the solvent. The solute determines many properties of the solution.

Example 2

medium

In carbonated water,

\text{CO}_2

gas is dissolved in water. Identify the solute and solvent, and explain what happens when the bottle is opened.

Example 3

medium

Two students disagree: one says 'a solid is always the solute, a liquid is always the solvent'. Refute this with two concrete examples.

Example 4

hard

A salt mixture contains

4.0\,\text{g}

NaCl (

M=58.5

) and

4.0\,\text{g}

KCl (

M=74.55

) dissolved together in water to

200\,\text{mL}

. Compute total

\text{Cl}^-

molar concentration.

Example 5

challenge

In rubbing alcohol (

70\%

IPA,

30\%

water), a chemist needs to identify which substance has the higher molarity. Use molar masses (

M_{\text{IPA}} = 60.10\,\text{g/mol}

M_{\text{H}_2\text{O}} = 18.02\,\text{g/mol}

) and assume density

0.875\,\text{g/mL}

for the solution.

Practice Problems

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

Example 1

easy

In a saline solution (salt water), what is the solute?

Example 2

hard

20°\text{C}

, the maximum solubility of

\text{NaCl}

in water is

36 \text{ g}

per

100 \text{ mL}

. If a student adds

50 \text{ g}

\text{NaCl}

100 \text{ mL}

of water at

20°\text{C}

, what happens? Calculate how much solute dissolves and how much remains undissolved.

Example 3

easy

In salt water, which component is the solute?

Example 4

easy

In sugar dissolved in tea, what is the solute?

Example 5

easy

In carbonated soda,

CO_2

Example 15

Example 25

easy

In bronze (mostly copper with about

12\%

tin), what is the solute?

Example 26

easy

In humid air, water vapor is dissolved in nitrogen/oxygen gas. What is the solute?

Example 27

easy

A doctor prescribes a

0.9\%

saline IV. The dissolved substance is salt; the rest is water. Identify the solute.

Example 28

medium

A juice contains

14\,\text{g}

of sugar,

0.5\,\text{g}

of vitamin C powder, and

0.1\,\text{g}

of natural flavor dissolved in

185.4\,\text{g}

of water. List solutes, the solvent, and total mass.

Example 29

medium

You add

25\,\text{g}

\text{KNO}_3

100\,\text{g}

water; solubility at this temperature is

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

. Identify the solute and state whether the solute fully dissolves.

Example 30

medium

A laboratory bottle is labeled '

2.0\,\text{M}

NaOH(aq)'. What is the solute, and what does the label tell you about its concentration?

Example 31

medium

In sterling silver (

92.5\%

Ag,

7.5\%

Cu), identify the solute and the resulting solution type.

Example 32

medium

In a

30.0\,\text{g}

sugar solution containing

4.5\,\text{g}

sugar, compute the mass percent of the solute.

Example 33

medium

Sea water averages about

3.5\%

NaCl by mass. In

1.0\,\text{kg}

of sea water, how much solute is present?

Example 34

medium

A student dissolves

5.85\,\text{g}

NaCl in enough water to make

250\,\text{mL}

of solution. Identify the solute and compute its molarity. (

M_{\text{NaCl}} = 58.5\,\text{g/mol}

)

Example 35

hard

A bottle is labeled '

70\%

isopropyl alcohol (IPA),

30\%

water'. A common claim is 'IPA is the solute because it's the active ingredient'. Critique this claim.

Example 36

hard

15.0\,\text{g}

of glucose (

M = 180.0\,\text{g/mol}

) and

5.85\,\text{g}

NaCl (

M = 58.5\,\text{g/mol}

) are dissolved in

500\,\text{mL}

water. List the solutes and find each one's molar concentration.

Example 37

hard

250\,\text{mL}

solution contains

0.50\,\text{M}

KCl. How many grams of solute were dissolved? (

M_{\text{KCl}} = 74.55\,\text{g/mol}

)

Example 38

hard

A solution is prepared by mixing

50\,\text{mL}

1.0\,\text{M}

NaCl with

50\,\text{mL}

water. Identify the solute and find its final concentration.

Example 39

hard

100\,\text{g}

saturated NaCl solution at

20°\text{C}

contains

26.5\%

NaCl. Find the mass of solute that crystallizes if the solution is evaporated until

40\,\text{g}

of water remains, with no more dissolving allowed.

Example 40

hard

A vinegar bottle is

5\%

acetic acid by mass. A

250\,\text{g}

bottle holds how much solute (acetic acid)? In moles, how much? (

M = 60.05\,\text{g/mol}

)

Example 41

challenge

0.100\,\text{M}

AgNO

_3

solution (

250\,\text{mL}

) is mixed with a

0.100\,\text{M}

NaCl solution (

250\,\text{mL}

). Identify the original solutes, then describe what happens to the Ag

^+

and Cl

^-

after mixing.

← Back to Solute Practice Mode

Related Concepts

Homogeneous Mixture Solvent Concentration

Background Knowledge

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

homogeneous mixture