Mole Concept Te...

The ratio by mass of magnesium and sulphur in magnesium sulphide is

The atomic mass of zinc is 65.37 u. Which of the following is the correct weight of 1 atom of zinc?

What is the correct number of hydrogen atoms in 0.25 mole of water?

Which of the following statements is/are correct?

(a) The word "mole" was introduced in 1896 by Wilhelm Ostwald.
(b) The mass of 1 mole of a substance is equal to its relative atomic or molecular mass in grams.
(c) The quantity of a substance can be characterised by the valency of its molecules.

Which of the following statements is/are correct?

(a) Naturally occurring oxygen is a mixture of atoms of slightly different masses called isotopes.
(b) Formula mass is used instead of molecular mass for a substance whose constituent particles are ions.
(c) Basic radicals carry negative charge.

Fluoride ion is a monovalent anion because it is a negative ion having a valency of one minus. Which of the following is also a monovalent anion?

Which of the following statements is/are false?

(a) Mole is a link between the mass of atoms and the number of atoms.
(b) The number 6.023 × 10²³, which represents a mole, is known as Avogadro's number.
(c) An atom represents the amount of a substance equal to its gram atomic mass.