Fundamental Concepts Of Chemistry Q 1-5

1. The soul of chemistry is its dealing with :

Internal structure changes in matter

Composition of matter

Properties of matter

Composition and properties of matter

Chemistry is the branch of science that focuses on the study of matter and its properties. It explores the composition of matter, which refers to the types and amounts of substances that make up a sample of matter. Additionally, chemistry also investigates the properties of matter, which include characteristics such as color, odor, density, and reactivity. Therefore, the answer "Composition and properties of matter" accurately describes the main focus of chemistry.

Explanation

Chemistry is the branch of science that focuses on the study of matter and its properties. It explores the composition of matter, which refers to the types and amounts of substances that make up a sample of matter. Additionally, chemistry also investigates the properties of matter, which include characteristics such as color, odor, density, and reactivity. Therefore, the answer "Composition and properties of matter" accurately describes the main focus of chemistry.

2. A chemist poured lemon juice on soil, the idea that he may have in his mind is that :

There may be a possibility of chemical reaction

Lemon juice is dangerous to health

Water should be preferred over lemon juice for drinking

Lemon juice is good for health

The chemist may have poured lemon juice on the soil to test if there is a possibility of a chemical reaction occurring. Lemon juice contains citric acid, which can react with certain compounds in the soil. This reaction could potentially have an effect on the soil's pH or nutrient composition. By conducting this experiment, the chemist may be trying to understand the impact of lemon juice on the soil and its potential for chemical reactions.

Explanation

The chemist may have poured lemon juice on the soil to test if there is a possibility of a chemical reaction occurring. Lemon juice contains citric acid, which can react with certain compounds in the soil. This reaction could potentially have an effect on the soil's pH or nutrient composition. By conducting this experiment, the chemist may be trying to understand the impact of lemon juice on the soil and its potential for chemical reactions.

3. All of the following statements are incorrect for 20 mol of hydrogen peroxide except

It has 20 mol of Hydrogen atoms

It has 30 mol of Oxygen atoms

It has 80 mol of atoms

It has 30 mol of Hydrogen atoms

The given answer is correct because the statement "It has 80 mol of atoms" is incorrect. Hydrogen peroxide (H2O2) consists of two hydrogen atoms and two oxygen atoms, so regardless of the number of moles, it will always have a total of 4 moles of atoms. The statement that it has 80 moles of atoms is incorrect and therefore the correct answer.

Explanation

The given answer is correct because the statement "It has 80 mol of atoms" is incorrect. Hydrogen peroxide (H2O2) consists of two hydrogen atoms and two oxygen atoms, so regardless of the number of moles, it will always have a total of 4 moles of atoms. The statement that it has 80 moles of atoms is incorrect and therefore the correct answer.

4. Dr. Khan has discovered two elements of an element with atomic number 119. The relative abundance of isotopes 119Uue300 and 119Uue305 is 70% and 30% respectively. The average atomic weight of Uue is:

301.5 a.m.u

302.5 a.m.u

303.5 a.m.u

304.5 a.m.u

The average atomic weight of Uue can be calculated by multiplying the atomic weight of each isotope by its relative abundance, and then summing these values. In this case, we have two isotopes: 119Uue300 with a relative abundance of 70% and an atomic weight of 300 a.m.u, and 119Uue305 with a relative abundance of 30% and an atomic weight of 305 a.m.u. Multiplying the atomic weights by their respective relative abundances and summing these values gives us (300 * 0.70) + (305 * 0.30) = 301.5 a.m.u. Therefore, the average atomic weight of Uue is 301.5 a.m.u.

Explanation

The average atomic weight of Uue can be calculated by multiplying the atomic weight of each isotope by its relative abundance, and then summing these values. In this case, we have two isotopes: 119Uue300 with a relative abundance of 70% and an atomic weight of 300 a.m.u, and 119Uue305 with a relative abundance of 30% and an atomic weight of 305 a.m.u. Multiplying the atomic weights by their respective relative abundances and summing these values gives us (300 * 0.70) + (305 * 0.30) = 301.5 a.m.u. Therefore, the average atomic weight of Uue is 301.5 a.m.u.

5. If [protcon number of two atoms is same then it can be concluded that:

They are isotopes

Compounds of both with cl2 will be similar in reactivity towards other compounds

Both have same color

Both have same melting points

If the protcon number of two atoms is the same, it can be concluded that compounds of both with Cl2 will be similar in reactivity towards other compounds. The protcon number is a measure of the number of protons in the nucleus of an atom, and it determines the chemical properties of an element. If two atoms have the same protcon number, it means they have the same number of protons and therefore similar chemical properties. When these atoms form compounds with Cl2, their reactivity towards other compounds will be similar because their chemical properties are the same.

Explanation

If the protcon number of two atoms is the same, it can be concluded that compounds of both with Cl2 will be similar in reactivity towards other compounds. The protcon number is a measure of the number of protons in the nucleus of an atom, and it determines the chemical properties of an element. If two atoms have the same protcon number, it means they have the same number of protons and therefore similar chemical properties. When these atoms form compounds with Cl2, their reactivity towards other compounds will be similar because their chemical properties are the same.