Compounds

Q.

Explain the law of definite proportions?

Q.

The law of definite proportions was proposed by:

Q.

What is the difference between $2\mathrm{O}$ and ${\mathrm{O}}_2$?

Q.

Can you extract sodium from salt?

Q.

4. A/An ____________ (element/compound) is a pure substance that cannot be broken down into simpler substances through chemical methods.

Q.

Is crude oil a mixture or a compound? Explain

Q.

Write the chemical names of the following compound: ${\left({\mathrm{CH}}_3\mathrm{COO}\right)}_2\mathrm{Pb}$

Q.

State law of definite proportion.

Q.

Define the law of conservation of mass and law of constant proportion?

Q.

The chemical formula for water present in two samples - distilled water and muddy water - are different.

1. True

2. False

Q.

A mixture is a combination of two or more pure substances.

1. True

2. False

Q. Which amongst the following is formed when two or more elements are chemically bonded together?

1. Mixture
2. Compound
3. Element
4. Atom

Q.

A substance that is composed of two or more elements, chemically combined with one another in a fixed proportion is called a ____.

1. compound

2. element

3. mixture

4. Solution

Q.

Is salt considered a metal or a non metal?

Q.

A compound is always heterogeneous.

1. True
2. False

Q.

State the law of Conservation of Mass and law of Constant Proportions.

Q.

Water is made up of hydrogen and oxygen.

1. True
2. False

Q. Which non-metal is used to disinfect water?​

Q.

In a chemical compound, the elements are always present in definite proportions by mass.

1. False

2. True

Q.

Classify the following as elements, compounds, and mixtures

Blood, fog, quick lime, sugar, carbon dioxide, carbon, iodine, vegetable oil, milk, butter

Q.

10. A molecule of sulfur has eight atoms. It is ________ .

1. An element

2. A compound

3. A mixture

4. Not matter

Q.

Write the chemical name of the following and also give their molecular formulae :

(a) Banking soda

(b) Vinegar

(c) Marble

(d) Sand

Q.

The formula of caustic potash is _____.

Q. Which of the following statements is correct?

1. some metallic hydrides are non-stoichiometric
2. Metallic hydrides conduct heat and electricity
3. Ionic hydrides do not conduct electricity in solid state
4. Ionic hydrides are very good conductors of electricity in solid state

Q.

Carbon dioxide consists of atoms of these two elements.

1. Carbon and Nitrogen

2. Carbon and Hydrogen

3. Carbon and Oxygen

4. None of these

Q. Phosphorus is stored in kerosene while sodium is stored in water to prevent them from reacting with air.

1. True
2. False

Q.

Fill in the blank:

A ____ is composed of two or more elements in a _______ proportion by weight.

Q.

How is sodium chloride different from its constituent elements ?

Q.

. Water and carbon dioxide are examples of compounds.

1. True
2. False

Q.

Which of the following statements about a compound is/are TRUE?

1. It is a pure substance.

2. Its constituents are combined chemically.

3. Its constituents do not retain their individual properties.

4. It can be separated by physical methods into its constituents.