Test your knowledge of mix types with 10 questions Next. Also check the comments after the feedback to answer your questions about the topic.
question 1
Consider the following systems:
I. Carbon dioxide and oxygen
II. water and alcohol
III. Granite
IV. Blood
The alternative that presents the correct sequence with the types of mixtures presented is:
there. homogeneous, II. heterogeneous, III. homogeneous and IV. homogeneous.
b) I. heterogeneous, II. homogeneous, III. heterogeneous and IV. homogeneous.
c) I. homogeneous, II. homogeneous, III. heterogeneous and IV. heterogeneous.
d) I. homogeneous, II. homogeneous, III. heterogeneous and IV. homogeneous.
Correct alternative: c) homogeneous, homogeneous, heterogeneous and heterogeneous.
Homogeneous mixtures are those consisting of more than one substance and present in a single phase, such as carbon dioxide + oxygen and water + alcohol systems.
Heterogeneous mixtures are materials made up of more than one component and that have more than one phase, so their properties vary in their extension. Examples of heterogeneous mixtures are granite and blood.
question 2
Although a pure substance such as distilled water and a homogeneous mixture such as mineral water may appear uniform in appearance, a pure substance differs from a homogeneous mixture by:
a) be visually clearer.
b) have greater chemical affinity.
c) present defined physical constants.
d) show greater interaction between molecules.
Correct alternative: c) present definite physical constants.
Pure substances, in addition to being formed by a single type of material, have well-defined physical constants, such as melting and boiling points at a given pressure.
Homogeneous mixtures are made up of more than one component and have a uniform appearance, but their properties, such as density, depend on the proportion of components in the mixture.
question 3
Adding table salt and sand to a glass of water creates a system:
a) homogeneous and biphasic.
b) homogeneous and single-phase.
c) heterogeneous and monophasic.
d) heterogeneous and biphasic.
Correct alternative: d) heterogeneous and biphasic.
Salt is a water-soluble substance and, therefore, when salt and water are mixed, a solution is formed, that is, a homogeneous mixture. However, the sand does not mix with water and as it is denser, it will settle at the bottom of the glass.
Thus, the system formed is heterogeneous and consists of two phases: phase I: sand and phase II: salt + water.
question 4
The materials water (I), vinegar (II) and oil (III) are added in two containers in the following order.
Container A: I, II and III
Container B: I, III and II
The number of phases in containers A and B are, respectively:
a) 1 and 2
b) 3 and 2
c) 2 and 3
d) 3 and 3
Correct alternative: c) 2 and 3.
Container A: water and vinegar (a mixture of water and acetic acid) are miscible, so when you add vinegar after the water there will be a mixture of the two components forming a single phase. Next, the addition of oil will form a second phase.
Container B: water and oil do not mix, as do oil and vinegar. Therefore, the container will have three phases.
question 5
Review the following statements.
I. Milk is a pure substance.
II. Carbon dioxide and oxygen form a homogeneous mixture.
III. Steel is a homogeneous mixture.
IV. Ethyl alcohol 96ºGL is a pure substance.
The statements are correct:
a) I and IV.
b) II and IV.
c) I and II.
d) II and III.
Correct alternative: d) II and III.
I. WRONG. Milk is a colloidal mixture.
II. CORRECT Carbon dioxide and oxygen form a homogeneous mixture.
III. CORRECT Steel is a homogeneous mixture, a metallic alloy formed by iron and carbon.
IV. WRONG. Ethyl alcohol 96 ºGL is a homogeneous mixture formed by 96% alcohol and 4% water.
question 6
Correctly match the mixture (column 1) with the number of phases (column 2).
| Column 1 | Column 2 |
| I. Water, Acetone, Granite, Sand and Ice | The. single phase |
| II. Water, ethanol and iron filings | B. biphasic |
| III. water, salt and sugar | ç. three-phase |
| IV. Water, salt, ice and sand | d. tetraphase |
The correct correspondents are:
a) I.b, II.a, III.c, IV.d
b) I.d, II.b, III.a, IV.c
c) I.c, II.d, III.b, IV.a
d) I.a, II.c, III.d, IV.b
Correct alternative: b) I.d, II.b, III.a, IV.c.
I.d. four phases: water + acetone, granite, sand and ice.
II.b. two phases: water + ethanol and iron filings.
III.a. stage one: salt and sugar are soluble in water.
IV.c. three phases: water + salt, ice and sand.
question 7
(UnB) Judge the items below, marking C for correct and E for wrong.
1) Water is a heterogeneous material that results from the meeting of hydrogen and oxygen.
2) Chemically pure materials are of natural origin.
3) Chemicals such as detergents and skin lotions contain more than one substance.
4) A substance will always constitute a single-phase system.
Correct answer: AND; AND; Ç; AND.
1) WRONG. Water is a substance formed by two atoms of hydrogen and one of oxygen. If rainwater, mineral water or drinking water were mentioned, we would have a homogeneous mixture, as in addition to water there are materials dissolved in it, such as mineral salts and oxygen.
2) WRONG. Pure materials can be synthesized or purification can be done in the laboratory.
3) CORRECT. Chemicals, such as detergents and skin lotions, contain more than one substance.
4) WRONG. Water and ice, for example, can form a two-phase system made up of just one substance.
question 8
(Cefet-CE) Applying the fundamental concepts of matter and energy, it is correct to state that:
a) any mixture of two solids is always homogeneous.
b) a mixture of several gases can be homogeneous or heterogeneous, depending on the proportion between them.
e) any mixture of a liquid plus a gas is always homogeneous.
d) water + salt and gasoline + alcohol mixtures are homogeneous in any proportion.
e) a pure substance can constitute a heterogeneous system when changing phases.
Correct alternative: e) a pure substance can constitute a heterogeneous system when changing phases.
A glass of water and ice, for example, can represent a two-phase system (liquid and solid), as well as boiling water (liquid and gas).
question 9
(UFRGS-RS) Analyze the material systems below, both at room temperature.
System I: mixture of 10 g of table salt, 30 g of fine sand, 20 ml of oil and 100 ml of water.
System II: mixture of 2.0 L of CO2, 3.0 L of N2 and 1.5 L of O2.
About these systems, it is correct to state that:
a) both are heterogeneous, as they have more than one phase.
b) in I, the system is biphasic, after strong agitation, and in II, it is monophasic.
c) in I, the system is three-phase, after strong agitation, and in II, it is single-phase.
d) both have a single phase, forming homogeneous systems.
e) in I, the system is three-phase, regardless of the order of addition of the components, and in II, it is two-phase.
Correct alternative: c) in I, the system is three-phase, after strong agitation, and in II, it is single-phase.
System I: three-phase system. Water + salt (homogeneous and colorless mixture), fine sand (insoluble solid) and oil (insoluble liquid in water).
System II: single-phase system. The mixture of gases always forms a homogeneous system, that is, it has only one phase.
question 10
(UFRGS) Consider the following properties of three liquid substances:
| Substance | Density (g/ml at 20°C) |
Solubility in water |
| Hexane | 0,659 | Insoluble |
| Carbon tetrachloride | 1,595 | Insoluble |
| Water | 0,998 | — |
By mixing equal volumes of hexane, carbon tetrachloride and water, a system will be obtained:
a) single-phase.
b) biphasic, in which the supernatant phase is hexane.
e) biphasic, in which the supernatant phase is carbon tetrachloride.
d) three-phase, in which the intermediate phase is carbon tetrachloride.
e) two-phase or three-phase, depending on the order of placement of the substances during the preparation of the mixture.
Correct alternative: e) two-phase or three-phase, depending on the order of placement of the substances during the preparation of the mixture.
A three-phase system can be formed by adding, in this order, carbon tetrachloride, water and hexane. If we add hexane and carbon tetrachloride together, they will only form one phase, as they are nonpolar liquids and due to chemical affinity they will mix.
Get more knowledge with the contents:
- Homogeneous and heterogeneous mixtures
- Pure substances and mixtures
- Separation of mixtures
- Exercises on separation of mixtures
