Which of the following options represents
Question: Which of the following options represents the correct bond order : (i) O2 O2 O2+ (ii) O2 O2 O2+ (iii) O2 O2 O2+ (iv) O2 O2 O2 Solution: Option (ii) is the answer....
Read More →Which of the following statement is not correct
Question: Which of the following statement is not correct from the viewpoint of molecular orbital theory? (i) Be2is not a stable molecule. (ii) He2is not stable but He2+ is expected to exist. (iii) Bond strength of N2 is maximum amongst the homonuclear diatomic molecules belonging to the second period. (iv) The order of energies of molecular orbitals in N2 molecule is 2s *2s 2pz (2px = 2py ) (*2px= *2py) *2pz Solution: Option (iv) is the answer....
Read More →Which of the following order of energies
Question: Which of the following order of energies of molecular orbitals of N2 is correct? (i) (2py ) (2pz) (*2px) (*2py) (ii) (2py ) (2pz) (*2px) (*2py ) (iii) (2py ) (2pz) (*2px) (*2py ) (iv) (2py ) (2pz) (*2px) (*2py ) Solution: Option (i) is the answer....
Read More →At what points will be tangents to the curve
Question: At what points will be tangents to the curve $y=2 x^{3}-15 x^{2}+36 x-21$ be parallel to the $x$ - axis? Also, find the equations of the tangents to the curve at these points. Solution: finding the slope of the tangent by differentiating the curve $\frac{d y}{d x}=6 x^{2}-30 x+36$ According to the question, tangent is parallel to the $x$-axis, which implies $m=0$ $6 x^{2}-30 x+36=0$ $x^{2}-5 x+6=0$ $x=3$ or $x=2$ since this point lies on the curve, we can find $y$ by substituting $x$ $...
Read More →The bond between B and C will be
Question: The bond between B and C will be (i) Ionic (ii) Covalent (iii) Hydrogen (iv) Coordinate Solution: Option (ii) is the answer....
Read More →The molecular formula of the compound
Question: The molecular formula of the compound formed from B and C will be (i) BC (ii) B2C (iii) BC2 (iv) BC3 Solution: Option (iv) is the answer....
Read More →The stable form of C may
Question: The stable form of C may be represented by the formula : (i) C (ii) C2 (iii) C3 (iv) C4 Solution: Option (ii) is the answer....
Read More →The stable form of A may
Question: The stable form of A may be represented by the formula : (i) A (ii) A2 (iii) A3 (iv) A4 Solution: Option (i) is the answer....
Read More →Find the equation of the tangent
Question: Find the equation of the tangent to the curve $x=\sin 3 t, y=\cos 2 t$ at $t=\frac{\pi}{4}$. Solution: finding the slope of the tangent by differentiating $x$ and $y$ with respect to $t$ $\frac{\mathrm{dx}}{\mathrm{dt}}=3 \cos 3 \mathrm{t}$ $\frac{\mathrm{dy}}{\mathrm{dt}}=-2 \sin 2 \mathrm{t}$ Dividing the above equations to obtain the slope of the given tangent $\frac{\mathrm{dy}}{\mathrm{dx}}=\frac{-2 \sin 2 \mathrm{t}}{3 \cos 3 \mathrm{t}}$ $\mathrm{m}$ (tangent) at $\frac{\pi}{4}$...
Read More →At the foot of a mountain, the angle of elevation of its summit is 45
Question: At the foot of a mountain, the angle of elevation of its summit is $45^{\circ}$. After ascending 1 km towards the mountain up an incline of $30^{\circ}$ the elevation changes to $60^{\circ}$ (as shown in the given figure). Find the height of the mountain. [Given $: \sqrt{3}=1.73]$ Solution: After ascending $1 \mathrm{~km}$ towards the mountain up an incline of $30^{\circ}$, the elevation changes to $60^{\circ}$ So, according to the figure given, $A B=A F \times \sin 30^{\circ}=(1 \time...
Read More →Which of the following angle
Question: Which of the following angle corresponds to sp2 hybridisation? (i) 90 (ii) 120 (iii) 180 (iv) 109 Solution: Option (ii) is the answer...
Read More →If the electronic configuration of an
Question: If the electronic configuration of an element is 1s2 2s2 2p6 3s2 3p6 3d2 4s2, the four electrons involved in chemical bond formation will be_____. (i) 3p6 (ii) 3p6, 4s2 (iii) 3p6, 3d2 (iv) 3d2, 4s2 Solution: Option (iv) 3d2, 4s2is the answer....
Read More →In which of the following substances
Question: In which of the following substances will hydrogen bond be strongest? (i) HCl (ii) H2O (iii) HI (iv) H2S Solution: Option (ii) H2Ois the answer....
Read More →Prove that
Question: Prove that $\left(\frac{\mathrm{x}}{\mathrm{a}}\right)^{\mathrm{n}}+\left(\frac{\mathrm{y}}{\mathrm{b}}\right)^{\mathrm{n}}=2$ touches the straight line $\frac{\mathrm{x}}{\mathrm{a}}+\frac{\mathrm{y}}{\mathrm{b}}=2$ for all $\mathrm{n} \in \mathrm{N}$, at the point $(\mathrm{a}, \mathrm{b})$. Solution: finding the slope of the tangent by differentiating the curve $n\left(\frac{x}{a}\right)^{n-1}+n\left(\frac{y}{b}\right)^{n-1} \frac{d y}{d x}=0$ $\frac{d y}{d x}=-\left(\frac{x}{y}\rig...
Read More →In which of the following molecule/ion
Question: In which of the following molecule/ion all the bonds are not equal? (i) XeF4 (ii) BF4- (iii) C2H4 (iv) SiF4 Solution: Option (iii) is the answer....
Read More →Which molecule/ion out of
Question: Which molecule/ion out of the following does not contain unpaired electrons? (i) N2+ (ii) O2 (iii) O22- (iv) B2 Solution: Option (iii)O22- is the answer....
Read More →A town B is 12 km south and 18 km west of a town A.
Question: A town B is 12 km south and 18 km west of a town A. Show that the bearing of $B$ from $A$ is $S 56^{\circ} 20^{\prime} W .$ Also, find the distance of $B$ from $A .$ Solution: Distance from $A$ to $B$ is $=\sqrt{12^{2}+18^{2}}=\sqrt{468}=21.63 \mathrm{Km}$ Let, bearing from $A$ to $B$ is $\theta$. So, $\tan \theta=\frac{18}{12}=\frac{3}{2}$ $\theta=\tan ^{-1}\left(\frac{3}{2}\right)=56.31^{\circ}=56^{\circ} 20^{\prime}$...
Read More →Find the equation of the tangent
Question: Find the equation of the tangent to the curve $x^{2}+3 y-3=0$, which is parallel to the line $y=4 x-5$ Solution: finding the slope of the tangent by differentiating the curve $3 \frac{d y}{d x}+2 x=0$ $\frac{d y}{d x}=-\frac{2 x}{3}$ $\mathrm{m}($ tangent $)=-\frac{2 \mathrm{x}}{3}$ equation of tangent is given by $y-y_{1}=m($ tangent $)\left(x-x_{1}\right)$ now comparing the slope of a tangent with the given equation $m($ tangent $)=4$ $-\frac{2 x}{3}=4$ $x=-6$ since this point lies o...
Read More →Which of the following species
Question: Which of the following species has tetrahedral geometry? (i) BH4- (ii) NH2- (iii) CO32- (iv) H3O+ Solution: Option (i)BH4-is the answer....
Read More →In NO3-ion, the number of bond
Question: In NO3-ion, the number of bond pairs and lone pairs of electrons on the nitrogen atom is (i) 2, 2 (ii) 3, 1 (iii) 1, 3 (iv) 4, 0 Solution: Option (iv) is the answer....
Read More →In PO43- ion the formal charge
Question: In PO43-ion the formal charge on the oxygen atom of PO bond is (i) + 1 (ii) 1 (iii) 0.75 (iv) + 0.75 Solution: Option (ii) is the answer....
Read More →Hydrogen bonds are formed in many compounds e.g.,
Question: Hydrogen bonds are formed in many compounds e.g., H2O, HF, NH3. The boiling point of such compounds depends to a large extent on the strength of hydrogen bond and the number of hydrogen bonds. The correct decreasing order of the boiling points of the above compounds is : (i) HF H2O NH3 (ii) H2O HF NH3 (iii) NH3 HF H2O (iv) NH3 H2O HF Solution: Option (ii) is the answer....
Read More →Find the equation of the tangent to the curve
Question: Find the equation of the tangent to the curve $y=\sqrt{3 x-2}$ which is parallel to the line $4 x-2 y+5=0$. Solution: finding the slope of the tangent by differentiating the curve $\frac{d y}{d x}=\frac{3}{2 \sqrt{3 x-2}}$ equation of tangent is given by $y-y_{1}=m(\operatorname{tangent})\left(x-x_{1}\right)$ now comparing the slope of a tangent with the given equation $\mathrm{m}($ tangent $)=2$ $\frac{3}{2 \sqrt{3 x-2}}=2$ $\frac{9}{16}=3 x-2$ $x=\frac{41}{48}$ since this point lies ...
Read More →The types of hybrid orbitals of nitrogen
Question: The types of hybrid orbitals of nitrogen in NO2+, NO3-and NH4+respectively are expected to be (i) sp, sp3 and sp2 (ii) sp, sp2 and sp3 (iii) sp2, sp and sp3 (iv) sp2, sp3 and sp Solution: Option (ii) is the answer....
Read More →Polarity in a molecule and hence
Question: Polarity in a molecule and hence the dipole moment depends primarily on electronegativity of the constituent atoms and shape of a molecule. Which of Does the following have the highest dipole moment? (i) CO2 (ii) HI (iii) H2O (iv) SO2 Solution: Option (iii) is the answer....
Read More →