The catenation tendency
Question: The catenation tendency of $\mathrm{C}, \mathrm{Si}$ and $\mathrm{Ge}$ is in the order $\mathrm{Ge}\mathrm{Si}\mathrm{C}$. The bond energies (in $\mathrm{kJ} \mathrm{mol}^{-1}$ ) of $\mathrm{C}-\mathrm{C}, \mathrm{Si}-\mathrm{Si}$ and $\mathrm{Ge}$ - Ge bonds are respectively :$348,260,297$$348,297,260$$297,348,260$$260,297,348$Correct Option: , 2 Solution:...
Read More →Which has trigonal bipyramidal shape ?
Question: Which has trigonal bipyramidal shape ?$\mathrm{XeOF}_{4}$$\mathrm{XeO}_{3}$$\mathrm{XeO}_{3} \mathrm{~F}_{2}$$\mathrm{XeOF}_{2}$Correct Option: , 3 Solution:...
Read More →Solve the equation
Question: If $\sum_{\mathrm{i}=1}^{9}\left(\mathrm{x}_{\mathrm{i}}-5\right)=9$ and $\sum_{\mathrm{i}=1}^{9}\left(\mathrm{x}_{\mathrm{i}}-5\right)^{2}=45$, then the standard deviation of the 9 items $\mathrm{x}_{1}, \mathrm{x}_{2}, \ldots . . \mathrm{x}_{9}$ is4239Correct Option: , 2 Solution:...
Read More →For the equilibrium,
Question: For the equilibrium, $\mathrm{A}(\mathrm{g}) \rightleftharpoons \mathrm{B}(\mathrm{g}), \Delta \mathrm{H}$ is $-40 \mathrm{~kJ} / \mathrm{mol}$. If the ratio of the activation energies of the forward $\left(\mathrm{E}_{\mathrm{f}}\right)$ and reverse $\left(\mathrm{E}_{\mathrm{b}}\right)$ reactions is $\frac{2}{3}$ then :-$\mathrm{E}_{\mathrm{f}}=60 \mathrm{~kJ} / \mathrm{mol} ; \mathrm{E}_{\mathrm{b}}=100 \mathrm{~kJ} / \mathrm{mol}$$\mathrm{E}_{\mathrm{f}}=30 \mathrm{~kJ} / \mathrm{m...
Read More →The number of values of k for which
Question: The number of values of $\mathrm{k}$ for which the system of linear equations, $(\mathrm{k}+2) \mathrm{x}+10 \mathrm{y}=\mathrm{k}$ $\mathrm{kx}+(\mathrm{k}+3) \mathrm{y}=\mathrm{k}-1$ has no solution is :infinitely many123Correct Option: , 2 Solution: Solution Not Required...
Read More →The shape of
Question: The shape of $\mathrm{IF}_{6}^{-}$is :Trigonally distorted octahedronPyramidalOctahedralSquare antiprismCorrect Option: 1 Solution:...
Read More →If the standard deviation of the numbers 2,
Question: If the standard deviation of the numbers 2, 3, a and 11 is 3.5, then which of the following is true ?$3 a^{2}-23 a+44=0$$3 a^{2}-26 a+55=0$$3 a^{2}-32 a+84=0$$3 a^{2}-34 a+91=0$Correct Option: , 3 Solution:...
Read More →An ellipse is drawn by taking a diameter of the circle
Question: An ellipse is drawn by taking a diameter of the circle $(x-1)^{2}+y^{2}=1$ as its semi-minor axis and a diameter of the circle $x^{2}+(y-2)^{2}=4$ as its semi-major axis. If the centre of the ellipse is at the origin and its axes are the coordinate axes, then the equation of the ellipse is :$x^{2}+4 y^{2}=16$$4 x^{2}+y^{2}=4$$x^{2}+4 y^{2}=8$$4 x^{2}+y^{2}=8$Correct Option: 1 Solution:...
Read More →An ellipse is drawn by taking a diameter of the circle
Question: An ellipse is drawn by taking a diameter of the circle $(x-1)^{2}+y^{2}=1$ as its semi-minor axis and a diameter of the circle $x^{2}+(y-2)^{2}=4$ as its semi-major axis. If the centre of the ellipse is at the origin and its axes are the coordinate axes, then the equation of the ellipse is :$x^{2}+4 y^{2}=16$$4 x^{2}+y^{2}=4$$x^{2}+4 y^{2}=8$$4 x^{2}+y^{2}=8$Correct Option: 1 Solution:...
Read More →The mean of the data set comprising of 16 observations is 16. I
Question: The mean of the data set comprising of 16 observations is 16. If one of the observation valued 16 is deleted and three new observations valued 3, 4 and 5 are added to the data, then the mean of the resultant data, is :15.814.016.816.0Correct Option: , 2 Solution:...
Read More →The reaction
Question: The reaction $2 \mathrm{~N}_{2} \mathrm{O}_{5}(\mathrm{~g}) \rightarrow 4 \mathrm{NO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g})$ follows first order kinetics. The pressure of a vessel containing only $\mathrm{N}_{2} \mathrm{O}_{5}$ was found to increase from $50 \mathrm{~mm} \mathrm{Hg}$ to $87.5 \mathrm{~mm} \mathrm{Hg}$ in $30 \mathrm{~min}$. The pressure exerted by the gases after $60 \mathrm{~min}$.$106.25 \mathrm{~nm} \mathrm{Hg}$$116.25 \mathrm{~nm} \mathrm{Hg}$$125 \mathrm{~m...
Read More →Bond distance in HF
Question: Bond distance in HF is $9.17 \times 10^{-11} \mathrm{~m}$. Dipole moment of $\mathrm{HF}$ is $6.104 \times 10^{-30} \mathrm{Cm}$. The percent ionic character in HF will be : (electron charge $=1.60 \times 10^{-19} \mathrm{C}$ )$61.0 \%$$38.0 \%$$35.5 \%$$41.5 \%$Correct Option: , 4 Solution:...
Read More →If the system of linear equations :
Question: If the system of linear equations : $x+a y+z=3$ $x+2 y+2 z=6$ $x+5 y+3 z=b$ has no solution, then :-$\mathrm{a}=-1, \mathrm{~b}=9$$a \neq-1, b=9$$\mathrm{a}=1, \mathrm{~b} \neq 9$$\mathrm{a}=-1, \mathrm{~b} \neq 9$Correct Option: 1, Solution: Solution Not Required...
Read More →The variance of first 50 even natural numbers is:-
Question: The variance of first 50 even natural numbers is:-$\frac{833}{4}$833437$\frac{437}{4}$Correct Option: , 2 Solution: $\therefore \sigma^{2}=3434-2601=833$...
Read More →Equation of the ellipse whose axes are the axes of coordinates
Question: Equation of the ellipse whose axes are the axes of coordinates and which passes through the point $(-3,1)$ and has eccentricity $\sqrt{2 / 5}$ is :-$3 x^{2}+5 y^{2}-15=0$$5 x^{2}+3 y^{2}-32=0$$3 x^{2}+5 y^{2}-32=0$$5 x^{2}+3 y^{2}-48=0$Correct Option: , 3 Solution:...
Read More →If the system of linear equations
Question: If the system of linear equations $x+k y+3 z=0$ $3 x+k y-2 z=0$ $2 x+4 y-3 z=0$ has a non-zero solution $(x, y, z)$, then $\frac{x z}{y^{2}}$ is equal to :10-3030-10Correct Option: 1 Solution: Solution Not Required...
Read More →Solve this
Question: $\mathrm{XeO}_{4}$ molecule is tetrahedral having :Two $\mathrm{p} \pi-\mathrm{d} \pi$ bondsFour $\mathrm{p} \pi-\mathrm{d} \pi$ bondsOne p $\pi-d \pi$ bondThree $\mathrm{p} \pi-\mathrm{d} \pi$ bondsCorrect Option: , 2 Solution:...
Read More →All the students of a class performed poorly in Mathematics.
Question: All the students of a class performed poorly in Mathematics. The teacher decided to give grace marks of 10 to each of the students. Which of the following statistical measures will not change even after the grace marks were given?meanmedianmodevarianceCorrect Option: , 4 Solution: Variance is independent of change of origin....
Read More →Solve this following
Question: Let $\overrightarrow{\mathrm{u}}$ be a vector coplanar with the vectors $\overrightarrow{\mathrm{a}}=2 \hat{\mathrm{i}}+3 \hat{\mathrm{j}}-\hat{\mathrm{k}}$ and $\overrightarrow{\mathrm{b}}=\hat{\mathrm{j}}+\hat{\mathrm{k}}$. If $\overrightarrow{\mathrm{u}}$ is perpendicular to $\overrightarrow{\mathrm{a}}$ and $\overrightarrow{\mathrm{u}} \cdot \overrightarrow{\mathrm{b}}=24$, then $|\overrightarrow{\mathrm{u}}|^{2}$ is equal to-31525684336Correct Option: Solution:...
Read More →The ellipse x^2+4 y^2=4 is inscribed in a rectangle aligned
Question: The ellipse $x^{2}+4 y^{2}=4$ is inscribed in a rectangle aligned with the coordinate axes, which in turn is inscribed in another ellipse that passes through the point $(4,0)$. Then the equation of the ellipse is :-$4 x^{2}+48 y^{2}=48$$4 x^{2}+64 y^{2}=48$$x^{2}+16 y^{2}=16$$x^{2}+12 y^{2}=16$Correct Option: , 4 Solution:...
Read More →Higher order (>3) reactions are rare due to :-
Question: Higher order (3) reactions are rare due to :-shifting of equilibrium towards reactants due to elastic collisionloss of active species on collisionlow probability of simultaneous collision of all the reacting speciesincrease in entropy and activation energy as more molecules are involved.Correct Option: , 3 Solution: Higher order (3) reaction are rare due to low probability of simulatneous collision of more than three molecuels....
Read More →Solve the equation
Question: Let $\mathrm{x}_{1}, \mathrm{x}_{2}, \ldots ., \mathrm{x}_{\mathrm{n}}$ be $\mathrm{n}$ observations, and let $\overline{\mathrm{x}}$ be their arithmetic mean and $\sigma^{2}$ be their variance. Statement-1 : Variance of $2 \mathrm{x}_{1}, 2 \mathrm{x}_{2}, \ldots, 2 \mathrm{x}_{\mathrm{n}}$ is $4 \sigma^{2}$. Statement-2 : Arithmetic mean of $2 x_{1}, 2 x_{2}, \ldots ., 2 x_{n}$ is $4 \bar{x}$.Statement1 is true, Statement2 is false.Statement1 is false, Statement2 is true.Statement1 i...
Read More →The solubility order for alkali metal fluoride in water is :
Question: The solubility order for alkali metal fluoride in water is :$\mathrm{LiF}\mathrm{NaF}\mathrm{KF}\mathrm{RbF}$$\mathrm{LiF}\mathrm{NaF}\mathrm{KF}\mathrm{RbF}$$\mathrm{RbF}\mathrm{KF}\mathrm{NaF}\mathrm{LiF}$$\mathrm{LiF}\mathrm{RbF}\mathrm{KF}\mathrm{NaF}$Correct Option: 1 Solution:...
Read More →Solve this following Question
Question: If $\left|\begin{array}{ccc}x-4 2 x 2 x \\ 2 x x-4 2 x \\ 2 x 2 x x-4\end{array}\right|=(A+B x)(x-A)^{2}$, then the ordered pair $(A, B)$ is equal to :$(-4,3)$$(-4,5)$$(4,5)$$(-4,-5)$Correct Option: , 2 Solution:...
Read More →A scientist is weighing each of 30 fishes.
Question: A scientist is weighing each of 30 fishes. Their mean weight worked out is 30 gm and a standard deviation of 2 gm. Later, it was found that the measuring scale was misaligned and always under reported every fish weight by 2 gm. The correct mean and standard deviation (in gm) of fishes are respectively :28, 432, 22, 428, 2Correct Option: , 2 Solution:...
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