Calculate the mass of one atom of hydrogen atom.
1 mole of hydrogen atom = 1g or 6.022 × 1023 atoms of hydrogen weigh = 1 g Mass of one atom = 1/6.022 𝑥 1023 𝑔 = 1.66058 ×…
Calculate the formula mass of sodium carbonate (Na2CO3.10H20).
Formula mass of sodium carbonate = (2 x atomic mass of Na) + (1 x atomic mass of C) + (3 x atomic mass of O) + 10 [(2 x…
Differentiate between the actual mass of a molecule and gram molecular mass.
Actual mass of a molecule is obtained by dividing the molar mass by Avogadro's number whereas gram molecular mass represents the molecular mass expressed in grams, i.e., it is the…
which of the following are tri-atomic and tetra-atomic molecules? CH3CI, CaCl2, NH3, PCl3, P205, H2O, C2H5OH.
(i) Tri-atomic molecules are CaCl2, H2O. (ii) Tetra-atomic molecules are NH3, PC13.
Which of the following symbols of elements are incorrect? Give their correct symbols. (a) Cobalt CO (b) Carbon c (c) Aluminium AL (d) Helium He (e) Sodium So
(a) Incorrect, the correct symbol of cobalt is Co. (b) Incorrect, the correct symbol of carbon is C. (c) Incorrect, the correct symbol of aluminium is Al. (d) Correct (He).…
Give an example to show law of conservation of mass applies to physical changes also.
Law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction. However, this law applies to physical changes also. For example, when ice…
How many times heavier is one atom of carbon than one atom of oxygen?
Atomic mass of carbon = 12 u Atomic mass of oxygen = 16 u Therefore, one atom of carbon is = 12 𝑢/16 𝑢 = 3/4 times heavier than one…
Dalton’s atomic theory is contradicted by the formula of sucrose (C12H22O11). Justify the statement.
Dalton's atomic theory states that atoms of different elements combine together in simple whole number ratio. In the formula of C12H22O11, the carbon, hydrogen and oxygen combine in whole number…
What is wrong in saying one mole of nitrogen?
The statement does not clarify whether we are talking about atoms or molecules of nitrogen. We should say 'one mole of nitrogen atoms' or 'one mole of nitrogen molecule’. tement…
The atomic number of three elements A, B and C are 9, 10 and 13 respectively. Which of them will form a cation?
Electronic configuration of A : 2,7 Electronic configuration of B : 2,8 Electronic configuration of C: 2, 8, 3 C" will form a cation because a cation is formed by…