|1 Crore+ students have signed up on EduRev. Have you?|
Q.1. Statement I: Acid strength increases in the order given as HF << HCl << HBr << HI.
Statement II: As the size of the elements F, Cl, Br, I increase down the group, the bond strength of HF, HCI, HBr, and HI decreases and so the acid strength increases.
In the light of the above statements, choose the correct answer from the options given below. (2021)
(a) Statement I is correct but Statement II is false.
(b) Statement I is incorrect but Statement II is true.
(c) Both Statement I and Statement II are true.
(d) Both Statement I and Statement II are false.
Down the group size increases
Acidic strength increases
Q.2. The incorrect statement about noble gases is - (2021)
(a) Noble gases have weak dispersion forces.
(b) Noble gases have large positive values of electron gain enthalpy.
(c) Noble gases are sparingly soluble in water.
(d) Noble gases have very high melting and boiling points.
Solution: Noble gases have weak dispersion forces so their melting and boiling point are very low.
Q.3. In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it? (2021)
(a) NH3 < PH3 < AsH3 < SbH3 : Increasing acidic character
(b) CO2 < SiO2 < SnO2 < PbO2 : Increasing oxidizing power
(c) HF < HCl < HBr < HI : Increasing acidic strength
(d) H2O < H2S < H2Se < H2Te : Increasing pKa values
Solution: Acidic strength of hydrides increase with increase in molecular mass. Thus order of acidic strength is
And as acidic strength increases, pKa decreases. Thus order of pKa
H2O < H2S < H2Se < H2Te
Q.4. Match the following : (2020)
Which of the following is correct option?
CO - Neutral
BaO - Basic
Al2O3 - Amphoteric
Cl2O7 - Acidic
Q.5. Urea reacts with water to form A which will decompose to form B. B when passed through Cu2+ (aq), deep blue colour solution C is formed. What is the formula of C from the following? (2020)
Q.6. Which of the following oxoacid of sulphur has –O–O– linkage? (2020)
(a) H2S2O8, peroxodisulphuric acid
(b) H2S2O7, pyrosulphuric acid
(c) H2SO3, sulphurous acid
(d) H2SO4, sulphuric acid
Q.7. Match the Xenon compounds in Column-I with its structure in Column-II and assign the correct code: (2019)
Q.8. Which is the correct thermal stability order for H2E (E = O, S, Se, Te and Po)? (2019)
(a) H2S < H2O < H2Se < H2Te < H2Po
(b) H2O < H2S < H2Se < H2Te < H2Po
(c) H2Po < H2Te < H2Se < H2S < H2O
(d) H2Se < H2Te < H2Po < H2O < H2S
On going down the group thermal stability order for H2E decreases because H–E bond energy decreases
∴ Order of stability would be:-
H2Po < H2Te < H2Se < H2S < H2O
Q.9. Which of the following statements is not true for halogens ? (2018)
(a) All form monobasic oxyacids.
(b) All are oxidizing agents.
(c) All but fluorine show positive oxidation states.
(d) Chlorine has the highest electron-gain enthalpy.
Due to high electronegativity and small size, F forms only one oxoacid, HOF known as Fluoric (I) acid. Oxidation number of F is +1 in HOF.
Q.10. In the structure of ClF3, the number of lone pairs of electrons on central atom 'Cl' is (2018)
2 lone pairs at equitorial position.
Q.11. Match the interhalogen compounds of column-I with the geometry in column II and assign the correct code. (2017)
Q.12. In which pair of ions both the species contain S–S bond? (2017)
Q.13. When copper is heated with conc. HNO3 it produces : (2016)
(a) Cu(NO3)2 and N2O
(b) Cu(NO3)2 and NO2
(c) Cu(NO3)2 and NO
(d) Cu(NO3)2 , NO and NO2
Nitric acid acts as an oxidising agent while reacting with copper.
i) when copper reacts with dilute nitric acid it forms,
3Cu + 4HNO3(dilute) → 3Cu(NO3)2 +2NO +4H2O
ii) When copper reacts with concentrated nitric acid it forms,
Cu +4HNO3(conc.) → Cu(NO3)2 +NO2 +2H2O
Q.14. Which is the correct statement for the given acids? (2016)
(a) Phosphinic acid is a diprotic acid while phosphonic acid is a monoprotic acid.
(b) Phosphinic acid is a monoprotic acid while phosphonic acid is a diprotic acid.
(c) Both are diprotic acids.
(d) Both are triprotic acids.
Phosphinic acid is a monoprotic acid while phosphonic acid is a diprotic acid.
Due to the presence of one replaceable proton in phosphinic acid, it is monoprotic acid and due to the presence of two replaceable proton in phosphinic acid, it is diprotic acid.
Q.15. Among the following, the correct order of acidity is : (2016)
(a) HCIO4 < HCIO2 < HCIO < HCIO3
(b) HCIO3 < HCIO4 < HCIO2 < HCIO
(c) HCIO < HCIO2 < HCIO3 < HCIO4
(d) HCIO2 < HCIO < HCIO3 < HCIO4
As oxidation number of central atom increases, acidic nature increases.
HClO < HClO2 < HClO3 < HClO4
Q.16. The product obtained as a result of a reaction of nitrogen with CaC2 is : (2016)
When calcium carbide reacts with nitrogen under high temperature, it forms calcium cyanamide which is also called nitrolim.
Q.17. Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules? (2016)
(a) F2 > Cl2 > Br2 > I2
(b) I2 > Br2 > CI2 > F2
(c) CI2 > Br2 > F2 > I2
(d) Br2 > I2 > F2 > CI2
Bond dissociation energies of halogen family decrease down the group as the size of the atom increases. The bond dissociation energy of fluorine, is, however, lower than those of chlorine and bromine because of interelectronic repulsions present in the small atom of fluorine.
Hence bond energy decreases in the order Cl2 > Br2 > F2 > I2
Q.18. Match the compound given in column I with the hybridization and shape given in column II and mark the correct option. (2016)
(a) XeF6 (i) distorted octahedral
(b) XeO3 (ii) square planar
(c) XeOF4 (iii) pyramidal
(d) XeF4 (iv) square pyramidal
(a) (b) (c) (d)
(a) (iv) (i) (ii) (iii)
(b) (i) (iii) (iv) (ii)
(c) (i) (ii) (iv) (iii)
(d) (iv) (iii) (i) (ii)
(i) (iii) (iv) (ii)
Q.19. Which of the following species contain equal number of σ - and π - bonds ? (2015)
Q.20. Nitrogen dioxide and sulphur dioxide have some properties in common. Which property is shown by one of these compounds, but not by the other ? (2015)
(a) is used as a food-preservative
(b) forms 'acid-rain'
(c) is a reducing agent
(d) is soluble in water
SO2 is used in the manufacture of sodium bisulphate (NaHSO3) which is used as preservatives for jams, jellies and squashes.
Q.21. Which of the following pairs of ions are isoelectronic and isostructural ? (2015)
Q.22. Maximum bond angle at nitrogen is present in which of the following ? (2015)
In all of the four molecules NO2- and NO2 have one lone pair thus bond angle is less than 1200 in the case of NO2- and more than 1200 in the case of NO2 but in the NO3- there is no lone pair hence all are bonding pairs leading to an ideal bond angle of 1200.
In NO2+, the is no lone pair only bond pair exist thus leading a bond angle is 1800.
Q.23. Acidity of diprotic acids in aqueous solutions increases in the order : (2014)
(a) H2Te < H2S < H2Se
(b) H2Se < H2Te < H2S
(c) H2S < H2Se < H2Te
(d) H2Se < H2S < H2Te
Acidic strength of hydrides increases as the size
of central atom increases which weakens the
M- H bond. Since, the size increases from S to Te
thus acidic strength follows the order.
Acidic nature ∝
S to Te size increases, bond dissociation enthalpy
decreases and acidic nature increases.