Advertisements
Advertisements
Question
An element X forms the following compounds with hydrogen, carbon and oxygen :
H2X, CX2, XO2, XO3
State the three valencies of element X which are illustrated by these compounds.
Advertisements
Solution
H2X:
Element / Ion H X
Valency 1 2
To stabilize the compound with hydrogen, two atoms of X are required. Therefore, the valency of X in this compound will be two.
CX2:
Element/ Ion C X
Valency 4 2
To stabilize the compound with carbon, two atoms of X are required. Thus, the valency of X in this compound is two.
XO2:
Elements / Ion X O
Valency 4 -2
To stabilize this compound with oxygen, four atoms of X are required. Thus, the valency of X in this compound is four.
XO3:
Elements/ Ion X O
Valency 6 -2
To stabilize this compound with oxygen, six atoms of X are required. Thus, the valency of X in this compound is six.
APPEARS IN
RELATED QUESTIONS
Write down the name of a compound represented by the following formula:
CaCl2
Give the name of the element present in the following compound:
Quick lime
What is meant by atomicity ? Explain with two examples.
In what form does oxygen gas occur in nature ?
One of the forms of a naturally occurring solid compound P is usually used for making the floors of houses. On adding a few drops of dilute hydrochloric acid to P, brisk effervescence are produced. When 50 g of reactant P was heated strongly, than 22 g of a gas Q and 28 g of a solid R were produced as products. Gas Q is the same which produced brisk effervescence on adding dilute HCl to P. Gas Q is said to cause global warming whereas solid R is used for white-washing.
- What is (i) solid P (ii) gas Q, and (iii) solid R.
- What is the total mass of Q and R obtained from 50 g of P ?
- How does the total mass of Q and R formed compare with the mass of P taken ?
- What conclusion do you get from the comparison of masses of products and reactant ?
- Which law of chemical combination is illustrated by the example given in this problem ?
What are (i) ionic compounds, and (ii) molecular compounds ? Give two examples of each type of compounds.
Explain the term – molecules. Give three examples of atoms of the same element forming a molecule. State the atomicity of the same.
Give one example of a polyatomic molecule.
Give a reason why –
Helium is considered monoatomic, but hydrogen a diatomic molecule.
Which of the following is a short and scientific way of representing one molecule of an element or compound?
