1st year chemistry subject is totally linked with 10th class chemistry subject so first everyone should get a grip on 10th chemistry otherwise, it will be very difficult. Actually chemistry is a very easy subject if we understand. It will be totally based on formulas experiments. It’s a interesting subject. So now we are going to discuss some 1st year chemistry important questions.
Long answer questions
- What are the postulates of Bohr’s model of hydrogen atom and discuss the various importance of this model by explaining the various series of line spectra in hydrogen atoms?
- Explain the significance of all the quantum numbers? And explain how are the quantum numbers n, 1 and m arrived at?
- Write a short note on Heisenberg’s uncertainty principle? Write its significance?
Periodic Table (Classification of elements and periodicity in properties)
- Define IE1 and IE2. Why is IE2>IE1 for a given atom? Discuss the factors affecting IE of an element?
- Explain what a periodic property is? How the following properties differ in a group and in a period? Explain
- Atomic radius
- Electronic gain enthalpy
- Ionisation energy
- Nature of oxides
- Metallic and non-metallic nature
- Write an essay on s, p, d, and f block elements?
Chemical bonding and molecular structure
- Explain the factors favorable for the formation of ionic compounds?
- Write N2 and O2 Molecules magnetic nature? Give the molecular orbital energy diagram of N2 and O2 by calculating the respective bond order?
- Explain the applications of VSEPR?
- Explain about Hybridisation with a suitable example?
- Give an equation for the reactions of ethylene with the following and describe two methods for preparation of ethylene?
- Cold and dil.alkKMnO4
- Hydrogen halide
- Give two methods for preparation of acetylene. How does it react with following give the corresponding equations
- Acetic acid
- Hydrogen halide
- Ammonical AgNO3 and Cu2Cl2
- Describe any two methods of preparation of benzene with corresponding equations. Explain the halogenations, alkylations, acylations, nitration and sulphonation of benzene Benzene does not behave like an alkenes, why explain the reason?
Short answer questions
Classification of elements and periodicity in properties
- Give any four characteristics properties of transaction elements?
- What are the rare earths and transuranic elements?
- What is meant by lanthanide contraction? What are its consequences?
- What is a diagonal relationship? Why do they show this relation? Give a pair of elements having a diagonal relationship?
- What is valency of an element? In the third period how does it vary with respect to hydrogen?
- Explain the hybridization involved in PCI5 and SF6 molecules?
- State differences between p and s bonds?
- Explain with an example of formation of coordination covalent bond?
- Explain B2 molecule is paramagnetic by using molecular orbital theory?
- Explain though nitrogen in ammonia is in sp3 hybridization, the bond angle deviates from 109°28. Explain?
- What is meant by hydrogen bond? Explain various types of hydrogen bonds with examples?
- Even though both NH3 and NF3 are pyramidal, NH3 has a high dipole moment compared to NF3. Why explain?
States of matter:Gases and liquid
- Explain a) Boyle’s law b) Charle’s law c) Graham’s law d) Dalton’s law e) Kinetic energy from kinetic gas equation?
- State and explain Graham’s law of diffusion and problem?
- State and explain Dalton’s law of partial pressures and problems?
- Define a) rms b) average c) most probable speeds of gas molecules and give their interrelationship and problem?
- Write kinetic molecular theory of gases postulates?
- Explain the importance of van der wall’s gas equation? Derive the van der waals equation of state?
- What is meant by ideal gas. Derive its equation?
- By oxidation number method balance the following equation
- Calculate the empirical formula of a compound having percentage composition: Potassium (K)=26.75, chromium(Cr)=35.36, Oxygen(O)=38.07 (Given the atomic weight of K, Cr and O as 39, 52, and 16 respectively)?
- Chemical analysis of a carbon compound gave the following percentage composition by weight of the elements present, carbon=10.6%, hydrogen=0.84%, chlorine89.10%. Calculate the empirical formula of compound?
- By ion-electron method balance the following reaction in acid medium
Hydrogen and its compounds
- Discuss the position of hydrogen in the periodic table on the basis of its electronic configuration?
- Explain and give the suitable examples for the following a) electron-deficient b) electron-precise c) electron-rich hybrids
- Write the chemical reaction to justify that hydrogen peroxide can function as an oxidizing as well as reducing agent?
- Explain extensive and intensive properties?
- State the first law of thermodynamics by its mathematical notation?
- What is the relationship between DU and DH that explains the state function ‘enthalpy’, H?
Chemical equilibrium and acids-bases
- Explain ionic products of water. What is its value at room temperature?
- What is meant by solubility product? For the following write the solubility expression a) Ag2Cr2O7 b) Zr3(PO4)4
- Give the classification of salts? What types of salts undergo hydrolysis?
The S-block elements
- Explain the preparation and properties of sodium carbonate?
- Discuss the biological importance of Na+, K+, and Mg+2, Ca+2 ions?
The P-block elements (Group 13)
- Explain the structure of diborane?
- What is meant by borax? Explain a borax bead test with a suitable example?
- What happens
a) Borax is heated strongly
b) Borax acid is added to water
c) Aluminium is heated with dilute NaOH
d) BF3 is treated with ammonia
e) Hydrated alumina is treated with aq.NaOH solution.
- What is ozonolysis? Which compound reacts with O3
- With any one example explain wurtz reaction and friedel crafts alkylation?
- Write the mechanism of halogenations of methane?
These are some of the important topic wise long and short questions which are very important. Everyone should learn these from which we can gain knowledge. Chemistry is a very easy and interesting subject which is very useful for all kinds of competitive exams.