Foundation level - IV NEET Mock test -9 ( Chemistry)

Which of the following statements is not true about an atom?

• Atoms are not able to exist independently.

• Atoms are the basic units from which molecules and ions are
  formed.

• Atoms are always neutral in nature.

• Atoms aggregate in large numbers to form the matter that we can see, feel or touch.

Tags

Atoms and molecules

1 u or 1 amu means

.

• Mass of C-12 atom

• Mass of O-16 atom

• 1/12th mass of C-12 atoms

• Mass of Hydrogen molecule

Tags

Atoms and molecules

Which of the following contains maximum number of molecules?

• 19 CO₂

• 1 g N₂

• 1 g CH₄

• 1 g H₂

Tags

Atoms and molecules

A sample of NH₃ molecule irrespective of source contains 82.35% Nitrogen and 17.65% of Hydrogen by mass. This data supports:

• Las of Multiple Proportions

• Law of Definite Proportions

• Avogadro’s Law

• Law of Conservation of Mass

Tags

Atoms and molecules

An element X is divalent and another element Y is tetravalent. The compound formed by these two elements will be:

• XY₄

• XY₂

• X₂Y

• Xy

Tags

Atoms and molecules

The molecular formula of potassium nitrate is ________.

• KNO

• KNO₃

• KON

• KNO₂

Tags

Atoms and molecules

3.42 g of sucrose are dissolved in 18 g of water in a beaker. The numbers of oxygen atoms in the solution are

• 6.022 ×10²¹

• 6.022 ×10²³

• 6.68 ×10²³

• 6.09 ×10²²

Tags

Atoms and molecules

Molecular mass is defined as the

• Mass of one atom compared with the mass of one atom of hydrogen

• Mass of one atom compared with the mass of one molecule

• None of the above

• Mass of one molecule of any substance compared with the mass of one atom of C – 12

Tags

Atoms and molecules

A change in the physical state can be brought about

• When energy is either given to, or taken out from the system

• Without any energy change

• only when energy is taken out from the system

• only when energy is given to the system

The atomic mass of sodium is 23. The number of moles in 46g of sodium is ________.

• 4

• 2

• 3

• 1