Question
Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements.
  1. Lithium and oxygen.
  2. Magnesium and nitrogen.
  3. Aluminium and iodine.
  4. Silicon and oxygen.
  5. Phosphorus and fluorine.
  6. Element 71 and fluorine.

Answer

  1. Li2O
  2. Mg3N2
  3. AlI3
  4. SiO2
  5. PF3 or PF5
  6. The element with the atomic number 71 is Lutetium (Lu). It has valency 3. Hence, the formula of the compound is LuF3.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Consider the reactions:

O3(g) + H2O2(l) → H2O(l) + 2O2(g)

Why it is more appropriate to write these reactions as:

O3(g) + H2O2(l) → H2O(l) + O2(g) + O2(g)

Also suggest a technique to investigate the path of the above redox reactions.

Find out the number of wave made by a Bohr electron in one complete revolution in its 3rd orbit.
What effect does branching of an alkane chain has on its boiling point?
Consider the reactions:

6CO2(g) + 6H2O(l) → C6H12O6(aq) + 6O2(g)

Why it is more appropriate to write these reactions as:

6CO2(g) + 12H2O(l) → C6H12O6(aq) + 6H2O(l) + 6O2(g)

Also suggest a technique to investigate the path of the above redox reactions.

What are the oxidation number of the underlined elements in the following and how do you rationalise your results?
CH3COOH
Arrange the elements N, P, O and S in the order of:

  1. Increasing first ionisation enthalpy.
  2. Increasing non metallic character. Give reason for the arrangement assigned.
The electronic configuration of some elements are given below:
a. $1 s^2, 2 s^2, 2 p^6, 3 s^2$
b. $1 s^2, 2 s^2, 2 p^6$
c. $1 s^2, 2 s^2, 2 p ^2$
d. $1 s^2, 2 s^2, 2 p ^6, 3 s^1$
e. $1 s^2, 2 s^2, 2 p^5$
Answer the following questions:
i. Name the elements.
ii. Which of these have the lowest Ionization enthalpy?
iii. Which is a halogen?
iv. Which is an alkali metal?
v. Which is an inert gas?
Describe the hybridization scheme in case of PCI5. Why are the axial bonds longer as compared to equitorial bonds.
What is the maximum number of emission lines when the excited electron of a H atom in n = 6 drops to the ground state?
  1. What is role of copper oxide in estimation of carbon and hydrogen?
  2. How do we test phosphorus in given organic compound?
  3. What is shape of $\stackrel{\oplus\ \ }{\text{CH}_3}$ (methyl carbocation) and $\stackrel{\oplus\ \ }{\text{CH}_3}$ (methyl carbanion)?