Q.1. Highest percentage of nitrogen is found in which among the following fertilizers among the given options?
[A] Calcium ammonium nitrate
[B] Ammonium nitrate
[C] Calcium nitrate
[D] Urea
Answer: D [Urea]
Notes:
The agricultural industry widely uses urea, a white crystalline solid containing 46 percent nitrogen as an animal feed additive and fertilizer. Urea has the highest nitrogen content of all solid fertilizers at 46% N.
Q.2. What is the general trend for ionization enthalpies of alkali metals as we move down the group?
[A] it increases
[B] it decreases
[C] it is same for all
[D] None
Answer: B [it decreases]
Notes:
The ionization enthalpies of the alkali metals are considerably low and decrease down the group from Li to Cs.
Q.3. Which of these is NOT a compound of carbon?
[A] Acetic acid
[B] Chloroform
[C] Caustic Soda
[D] Methane
Answer: C [Caustic Soda]
Notes:
Caustic soda is a compound of sodium where as Acetic acid, Chloroform and Methane are the compounds of carbon.
Q.4. Which of the following is emitted in alpha decay?
[A] Helium nucleus
[B] Hydrogen nucleus
[C] Electrons
[D] Carbon nucleus
Answer: A [Helium nucleus]
Notes:
In alpha decay, Helium nucleus is emitted. Alpha decay or a-decay is a type of radioactive decay in which an atomic nucleus transforms or ‘decays’ into a different atomic nucleus, with a mass number that is reduced by four and an atomic number that is reduced by two.
Q.5. Which of these non-metals is liquid at room temperature?
[A] Helium
[B] Argon
[C] Bromine
[D] Sulphur
Answer: C [ Bromine ]
Notes:
Among all the non-metals, Bromine exists in the liquid state at room temperature. All the other non-metals are either solids or gases in nature.
Q.6. Which compound of mercury is used as antiseptic?
[A] Mercuric sulphide
[B] Mercuric oxide
[C] Mercuric chloride
[D] Mercuric iodide
Answer: C [Mercuric chloride]
Notes:
Mercury chloride (HgCl2) is a highly toxic compound that volatizes slightly at ordinary temperature and appreciably at 100 degrees C. It is corrosive to mucous membranes and used as a topical antiseptic and disinfectant.
Q.7. Choose the incorrect statement:
[A] Slaked lime is also known as Calcium hydroxide
[B] Suspension of slaked lime is known as Milk of lime
[C] Aqueous solution of slaked lime is known as quick lime
[D] Both a and b
Answer: C [Aqueous solution of slaked lime is known as quick lime]
Notes:
Calcium hydroxide(Slaked lime) is prepared by adding water to quick lime, CaO. Suspension of slaked lime is known as Milk of lime and aqueous solution of slaked lime is known as lime water.
Q.8. Which of the following is correct?
[A] A colloidal solution is a heterogeneous mixture
[B] A colloidal solution is a homogeneous mixture
[C] The particles of a colloidal solution cannot scatter beam of light
[D] None of the above
Answer: A [A colloidal solution is a heterogeneous mixture]
Notes:
Due to the relatively smaller size of particles, as compared to that of a suspension, the mixture appears to be homogeneous. But actually, a colloidal solution is a heterogeneous mixture. The particles can easily scatter a beam of visible light.
Q.9. What do we call the reaction when an acid and a base react together to form salt and water?
[A] Reduction Reaction
[B] Oxidation Reaction
[C] Neutralisation Reaction
[D] Combination Reaction
Answer: C [Neutralisation Reaction]
Notes:
When an acid and a base react together to form salt and water, the reaction is known as Neutralisation Reaction. HCl (aq) + NaOH (aq) ? H2O (l) + NaCl (aq) (acid) (base) (Water) (Salt) Hydrochloric acid Sodium hydroxide Sodium Chloride
Q.10. What is the nature of Drinking soda?
[A] Alkaline
[B] Acidic
[C] Neutral
[D] Oxidant
Answer: B [Acidic]
Notes:
Drinking soda is acidic in nature. Cherry coke was found to be the next most acidic (pH of 2.522), and Coke was the third most acidic soda tested (pH of 2.525). The type of acid in the soda, level of soda and calcium content are also factors. Citric acid is the most erosive acid found in soft drinks and is the predominant acid in non-cola drinks.
Q.11. The exceptionally low melting point of mercury can be explained on the basis of which of the following explanations?
- Mercury has completely filled-up atomic orbitals
- In mercury, the binding energy of outer electrons (towards nucleus) is highest and no electron is available to participate in metallic bond formation
Choose the correct option from the codes given below:
[A] Only 1 is correct
[B] Only 2 is correct
[C] Both 1 & 2 are correct
[D] Neither 1 nor 2 is correct
Answer: C [ Both 1 & 2 are correct]
Notes:
Mercury belongs to the zinc group of elements in the periodic table, which comprises zinc, cadmium and mercury. They all have completely filled-up atomic orbitals. It becomes difficult to knock out these electron(s) from their orbitals and form metallic bonds. With its filled shell electron configuration it is very reluctant to form bonds even with other mercury atoms.
Q.12. Which of the following is correct about Potassium carbonate?
[A] Its chemical formula is K CO3
[B] It is a salt which is white in colour
[C] It is used in the production of soap
[D] All of the above
Answer: D [All of the above]
Notes:
Potassium carbonate is a salt which is white in colour. It is used in the production of soap. Its chemical formula is K2 CO3.
Q.13. Which of the following refining methods works on the principle that impurities are more soluble in the melt than in the solid state of the metal?
[A] Liquation
[B] Electrolytic refining
[C] Zone refining
[D] Vapour Phase refining
Answer: C [Zone refining]
Notes:
Zone refining works on the principle that impurities are more soluble in the melt than in the solid state of the metal. This method is very useful for producing semiconductors.
Q.14. What is the sum of powers of the concentration of the reactants called as?
[A] Order of reaction
[B] Stage of reaction
[C] Zone of reaction
[D] None of the above
Answer: A [Order of reaction]
Notes:
The sum of powers of the concentration of the reactants in the rate law expression is known as the order of that chemical reaction.
Q.15. Chewing gum is made from which of the following?
[A] Resin
[B] Polystyrene
[C] Polyvinyl acetate
[D] Latex
Answer: D [Latex]
Notes:
Chewing gum was made of a substance called chicle mixed with flavorings. Chicle is a latex sap that comes from the sapodilla tree (native to Central America).
Q.16. PVC is a polymer of ?
[A] Propane
[B] Vinyl chloride
[C] Styrene
[D] Carbonates
Answer: B [Vinyl chloride]
Notes:
Polyvinyl chloride (PVC) is made from the monomer vinyl chloride (CH2 =CHCl). It is used for making rain coats, handbags, toys including dolls, electrical goods and as a covering of electrical wires.
Q.17. What is the force that is required to produce unit elongation in a wire known as?
[A] Bulk modulus
[B] Thermal strain
[C] Thermal stress
[D] Force constant
Answer: D [Force constant]
Notes:
Force constant of material of wire is the force required to produce unit elongation in a wire. It is denoted by k. K = F/l or K = YA/l
Q.18. How many values of Magnetic quantum numbers are possible for any sub-shell (l)?
[A] 2l
[B] 2l + 1
[C] 2l -1
[D] l
Answer: B [2l + 1]
Notes:
For any sub-shell (l), 2l+1 values of Magnetic quantum numbers (ml) are possible.
Q.19. Which of the following statements is correct?
[A] pH scale measure the hydrogen ion concentration
[B] pH of a neutral solution is 10
[C] Both a and b
[D] None
Answer: A [pH scale measure the hydrogen ion concentration]
Notes:
pH scale is a scale for measuring hydrogen ion concentration in a solution, called pH scale has been developed. The p in pH stands for ‘potenz’ in German, meaning power. On the pH scale we can measure pH generally from 0 (very acidic) to 14 (very alkaline). The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution.
Q.20. Which of these drugs is called as the ‘love drug’?
[A] Mescalin
[B] MDMA
[C] Dextromethorphan
[D] Ketamine
Answer: B [ MDMA]
Notes:
MDMA or 3,4-methylenedioxy-methamphetamine is a synthetic drug that alters mood and perception (awareness of surrounding objects and conditions). It is called as the love drug when used recreationally.