Matters and Properties of Matters Exam 1 and Problem Solutions

Matters and Properties of Matters Exam 1 and Problem Solutions

1. Which ones of the following statements are chemical property of CO₂ gas?

I. It is not combustive matter

II. It is heavier than air

III. It dissolves better in water

Solution:

I. Being combustive element or not shows whether CO₂ reacts with O₂ or not, so I is a chemical property of CO₂.

II. Being heavier than air is a physical property of CO₂. We can understand that density of CO₂ is larger than density of air.

III. Solubility in water is a physical property of CO₂.

2. Which ones of the following properties of pure liquid do not change with amount of matter?

I. Boiling point

II. Melting Point

III. Volume

IV. Density

Solution:

Boiling point and melting point  do not depend on amount of matter and they are distinguishing properties of matter.

Volume depends on amount of matter. When amount of matter increases, then volume of it also increases.

Density s distinguishing property of matter and does not depend on amount of matter.

3. Find given matters are homogeneous or heterogeneous mixtures.

I. Sugar

II. Milk

III. Salt water mixture

IV. Gas mixtures

V. Ice water mixture

VI. Naphthalene water mixture

Solution:

I, III and IV are homogeneous matters and;

II, V and VI are heterogeneous matters.

4. Which ones of the following statements related t classifications of matters are false?

I. Elements come together in definite proportions and form compounds

II. All mixtures are homogeneous matter

III. All elements are pure matter

Solution:

Elements come together in definite proportions and produce compounds I is true. All mixtures are not homogeneous matter, they can also be heterogeneous like milk, II is false. All elements are pure matters, III is true.

5. X, Y and Z matters are in room temperature and includes different types of atoms. When we give heat to Z, it decompose to X and Y matters. During melting process, temperatures of X and Y stay constant but temperature of Z changes. Which ones of the following statements are false for this situation?

I. Z is a pure compound formed by two different matters.

II. X and Y are pure matters

III. Z is formed by X and Y matters.

Solution:

Since temperatures of X and Y stay constant, they are pure substances and Z is not pure substance. X and Y includes different types of atoms, so they are compounds and Z is mixture.

6. Which one of the followings is not  distinguishing property of liquids.

I. Density

II. Freezing point

III. Refractive index

IV. Coefficient of linear expansion

Solution:

Coefficient of linear expansion is distinguishing property of matters having specific geometric shapes. It is change in the length of matter when its temperature is changed 1 ⁰C. Since liquids do not have specific shapes we can not talk about linear expansion of them. All others are distinguishing property for liquids.