Chemistry
Which of the following reactions is not correct according to the laws?
P4 + 5O2 ⟶ P4O10
C2H6 ⟶ CO2 + H2O
2Zn + O2 ⟶ 2ZnO
CH4 + 2O2 ⟶ CO2 + 2H2O
Answer
C2H6 ⟶ CO2 + H2O
Reason — C2H6 ⟶ CO2 + H2O
This equation does not follow the Law of conservation of mass because reactant side has 2 carbon atoms and 6 hydrogen atoms whereas product side has only 1 carbon atom and 2 hydrogen atoms. Since both the sides do not have the same number of atoms, it violates the Law of conservation of mass which states that matter can neither be created nor destroyed in a chemical reaction.
Other reactions are balanced. The total number of atoms of each element on the reactants side, is the same as the number of atoms in the products formed, in the equation. So, they follow the Law of conservation of mass.
Related Questions
One "μ" stands for :
- One atom of any element
- 1/12th of hydrogen atom
- An atom of carbon (C-12)
- 1/12th the mass of carbon atom (C-12).
Which of the following statements about a compound is incorrect ?
- A molecule of a compound has atoms of different elements.
- A compound cannot be separated into its constituent elements by physical methods of separation.
- A compound retains the physical properties of its constituent elements.
- The ratio of atoms of different elements in a compound is fixed.
In the compound magnesium nitride (Mg3N2):
P — Mg is trivalent, N is divalent.
Q — Mg is divalent. N is trivalent.
R — Mg is divalent, N is divalent.
Which of the statements given above is/are true?
Only P
Only Q
Only R
Both P and Q
Copper shows variable valency and forms two different compounds with oxygen — Cu2O and CuO.
P — A is cuprous oxide, B is cupric oxide.
Q — A is cupric oxide, B is cuprous oxide.
R — A is copper (I) oxide, B is copper (II) oxide.
Only P
Only Q
Only R
Both P and R