List of practice Questions

Consider the following statements
Statement I: Benzene undergoes electrophilic substitution with excess chlorine in the presence of anhydrous AlCl$_3$
Statement - II: Benzene also undergoes electrophilic substitution with chlorine in the presence of UV light.
The correct answer is
NaCl is crystallized in the presence of small quantity of SrCl$_2$. The formula of crystallized solid is Na$_{0.9998}$Sr$_{0.0001}$Cl. The number of cationic vacancies per mole of this solid is (N=6$\times10^{23}$ mol$^{-1}$)
Elements A and B form two non-volatile compounds (AB$_2$ and AB$_4$). When 1 g of AB$_2$ is added to 20 g of C$_6$H$_6$ (molar mass =78 gmol$^{-1}$) the freezing point of C$_6$H$_6$ is lowered by 2.3 K. When 1 g of AB$_4$ is added to 20 g of C$_6$H$_6$, the freezing point of C$_6$H$_6$ was lowered by 1.3 K. The atomic masses of A and B are respectively (K$_f$(C$_6$H$_6$)=5.1 K kg mol$^{-1}$)
Identify the correct statements from the following
I. In CuSO$_4\cdot5$H$_2$O, only one molecule of H$_2$O is hydrogen bonded.
II. In BaCl$_2\cdot2$H$_2$O, water is in interstitial positions
III. In CrCl$_3\cdot6$H$_2$O, only three H$_2$O molecules form coordinate bonds with Cr$^{3+}$
Identify the correct statements
I. Lithium halides are somewhat covalent in nature
II. NaNO$_3$ on heating gives NO$_2$ gas
III. LiHCO$_3$ is a solid
IV. All alkali metals form ethynides on reaction with ethyne
Which of the following compounds are correctly matched with their uses?
The correct order of atomic radii of Al, Ga, In, Tl is
Which of the following set of Oxides is not correctly matched?
In long form of periodic table an element 'X' is present in group 'Y' in which Mn is also an element. X, Y respectively are
Identify the number of metalloids from the following: Sb, Be, P, Ge, Te, S, Cs, Tc, I
The slope of isobar of one mole of an ideal gas at p (atm) is 0.082 L K$^{-1}$. What is the value of p in atm? (R=0.082 L atm mol$^{-1}$K$^{-1}$)
At T(K) 10 L of an ideal gas was expanded to 12 L against a pressure of 2 atm irreversibly. What is the work done by the gas?
If the mean life of a radioactive sample is 10 minutes, then the time (in minutes) taken for the activity of the radioactive sample to become $\mathrm{e}^{21}$ times its initial activity is
In a nuclear fusion reaction, if the mass defect is 0.25%, then the energy released in the fusion of 400 $\mu$g mass of a substance is
A Zener diode of breakdown voltage 6 V is connected as shown in the circuit. The power dissipated in the Zener diode is
Five logic gates are connected as shown in the figure. If the inputs are A=C=1 and B=D=0, then the values of y1 and y2 respectively are
The height of a television transmitting antenna is 70 m. If the receiving antenna is at the ground level, then the service area covered by the transmitting antenna is nearly (Radius of the earth = 6400 km)
A galvanometer of resistance 8 $\Omega$ gives full scale deflection for a current of 4 mA. The resistance to be connected in series to the galvanometer to convert it into a voltmeter to measure a maximum potential difference of 20 V is
If the magnetization of a bar magnet of area of cross-section 0.75 cm$^2$ and magnetic moment 2.7 Am$^2$ is $4 \times 10^5$ Am$^{-1}$, then the length of the magnet is
A wheel with 12 metallic spokes each 40 cm long is rotated with an angular speed of 15 rads$^{-1}$ in a plane normal to the horizontal component of earth's magnetic field. If the horizontal component of earth's magnetic field at the place is $4\times10^{-5}$ T, then the induced emf between the axle and the rim of the wheel is
A 132 V ac source is connected to a pure inductor of inductance 140 mH. If the frequency of the ac source is 50 Hz, then the current passing through the inductor is
Klystron valve is used to produce
The de Broglie wavelength associated with an electron accelerated through a potential difference of 2400 V is nearly
The distance of closest approach of an alpha particle from a nucleus when the alpha particle moves towards a nucleus with a kinetic energy 'E' is 'x'. The distance of closest approach when the alpha particle approaches the same nucleus with kinetic energy 0.4E is
When three particles each having a positive charge $q$ are placed at the three vertices of an equilateral triangle, then the electrostatic force between any two particles is $F$. If a fourth particle of charge $3q$ is placed at the midpoint of one of the sides of the triangle, then the net electrostatic force on the fourth particle due to the remaining three particles is