Recent questions tagged 81

In the circuits shown below, the readings of the voltmeters and the ammeters will be:

asked Jul 8, 2019 by pady_1

1 answer

A mixture contains four solid organic compounds A, B, C, D. On heating only C changes from solid to vapours state. C can be separated from the rest in the mixture by :

asked Dec 19, 2018 by pady_1

1 answer

The oxidation number of nitrogen in $NH_3$ is:

asked Dec 19, 2018 by pady_1

0 answers

Brass is an alloy of :

asked Dec 19, 2018 by pady_1

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The energy of an electron present in Bohr's second orbit of hydrogen atom is :

asked Dec 11, 2018 by pady_1

1 answer

Acetylene does not react with :

asked Dec 11, 2018 by pady_1

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Which one of the following statements is correct ?

asked Dec 11, 2018 by pady_1

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The recommended concentration of fluoride ion in drinking water is up to 1 ppm as fluoride ion is required to made teeth enamel harder by converting $ [3Ca_3(PO_4)_2.Ca(OH)_2]$ to:

asked Dec 11, 2018 by pady_1

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Two reactions $R_1$ and $R_2$ have identical pre-exponential factors. Activation energy of $R_1$ exceeds that of $R_2$ by $10\;kJ\; mol^{–1}$ . If $k_1$ and $k_2$ are rate constants for reactions $R_1$ and $R_2$ respectively at $300\; K$, then $ln(k_2/k_1)$ is equal to : $(R = 8.314 \;J mol^{–1} K ^{–1} )$

asked Dec 11, 2018 by pady_1

0 answers

Let P be the point on the parabola, $y^2=8x$ which is at a minimum distance from the centre C of the circle, $x^2+(y+6)^2=1$. Then the equation of the circle, passing through C and having its centre at P is :

asked Dec 11, 2018 by pady_1

1 answer

If the tangent to the conic, $y-6=x^2$ at $(2, 10)$ touches the circle, $x^2+y^2+8x-2y=k$ (for some fixed $k$) at a point $(\alpha, \beta)$; then $(\alpha, \beta)$ is:

asked Dec 11, 2018 by pady_1

1 answer

Considering the basic strength of amines in aqueous solution, which one has the smallest $pK_b$ value?

asked Dec 11, 2018 by pady_1

0 answers

An ideal gas enclosed in a vertical cylindrical container supports a freely moving piston of mass M. The piston and cylinder have equal cross sectional area A. When the piston is in equilibrium, the volume of the gas is $V_0$ and its pressure is $P_0$. The piston is slightly displaced from the equilibrium position and released. Assuming that the system is completely isolated from its surrounding, the piston executes a simple harmonic motion with frequency:

asked Dec 11, 2018 by pady_1

0 answers

Iron exhibits +2 and +3 oxidation states. Which of the following statements about iron is incorrect ?

asked Dec 11, 2018 by pady_1

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Which of the following statements regarding sulpher is incorrect ?

asked Dec 11, 2018 by pady_1

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The line L given by $\frac{x}{5}+ \frac{y}{b} = 1$ passes through the poin (13, 32). The line $K$ is parallel to $L$ and has the equation $\frac{x}{c}+\frac{y}{3}=1$. Then the distance between $L$ and $K$ is

asked Dec 11, 2018 by pady_1

0 answers

One ticket is selected at random from 50 tickets numbered $00, 01, 02, .....49$. Then the probability that the sum of the digits on the selected ticket is 8, given that the product of these digits is zero, equals

asked Nov 29, 2018 by pady_1

0 answers

A body of mass m = 3.513 kg is moving along the x-axis with a speed of $5.00 ms^{-1}$. The magnitude of its momentum is recorded as

asked Nov 29, 2018 by pady_1

1 answer

The energies of activation for forward and reverse reactions for $A_2 + B_2 \leftrightharpoons 2AB$ are $180\; kJ\;mol^{-1}$ and $200 \; kJ \;mol^{-1}$ respectively. The presence of a catalyst lowers the activation energy of both (forward and reverse) reactions by $100\; kJ\; mol^{-1}$. The enthalpy change of the reaction ($A_2 + B_2 \to 2AB$) in the presence of catalyst will be (in $kJ\;mol^{-1}$) :

asked Nov 29, 2018 by pady_1

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Which one of the following sets of ions represents a collection of isoelectronic species ?

asked Nov 13, 2018 by pady_1

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Which of the following is a polyamide ?

asked Nov 5, 2018 by pady_1

0 answers

Which one of the following sets of ions represents the collection of isoelectronic species ?

asked Nov 5, 2018 by pady_1

1 answer

Iron carbonyl, $Fe(CO)_5$ is

asked Aug 21, 2018 by pady_1

1 answer

Transplantation of tissues/ organs fails often due to non-acceptance by the patient's body. Which type of immuneresponse is responsible for such rejections?

asked Aug 21, 2018 by pady_1

1 answer

Which of the following statements is not true for cancer cells in relation to mutations ?

asked Aug 21, 2018 by pady_1

1 answer

The body cell in cockroach discharge their nitrogenous waste in the haemolymph mainly in the form of -

asked Aug 21, 2018 by pady_1

1 answer

Which of the following organic compounds polymerizes to form the polyester Dacron?

asked Aug 20, 2018 by pady_1

1 answer

The structure of isobutyl group in an organic compound is-

asked Aug 20, 2018 by pady_1

1 answer

Which of the following statements is not valid for oxoacids of phosphorus ?

asked Aug 20, 2018 by pady_1

1 answer

Name the type of the structure of silicate in which one oxygen atom of $[SiO_4]^{4–}$ is shared ?

asked Aug 16, 2018 by pady_1

1 answer

In a buffer solution containing equal concentration of $B^-$ and HB, the $K_b$ for $B^-$ is $10^{-10}$. The pH of buffer solution is:

asked Jul 26, 2018 by pady_1

1 answer

Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states ?

asked Jul 26, 2018 by pady_1

1 answer

The value of equilibrium constant of the reaction, <br> $HI(g)\rightleftharpoons \frac{1}{2}H_2(g)+\frac{1}{2}I_2(g)$ is 8.0. <br> The equilibrium constant of the reaction, <br> $H_2(g)+I_2(g)\rightleftharpoons2HI(g)$ will be -

asked Jul 26, 2018 by pady_1

1 answer

Which one of the following ions is the most stable in aqueous solution ? <br> (At. No. Ti = 22, V = 23, Cr = 24, Mn = 25)

asked Jul 26, 2018 by pady_1

1 answer

1.00 g of a non-electrolyte solute (molar mass $250g mol^–1$) was dissolved in 51.2 g of benzene. If the freezing point depression constant $K_f$ of benzene is $5.12 K kg mol^{–1}$, the freezing point of benzene will be lowered by:-

asked Jul 25, 2018 by pady_1

0 answers

Which of the following molecules has trigonal planer geometry ;

asked Jul 24, 2018 by pady_1

1 answer

Which is the best description of the behavior of bromine in the reaction given below:-$H_2O+Br_2\to HOBr+HBr$

asked Jul 24, 2018 by pady_1

1 answer

Which one of the following characteristics of the transition metals is associated with their catalytic activity :

asked Jul 24, 2018 by pady_1

1 answer

$CuSO_4$ when reacts with KCN forms CuCN, which is insoluble in water. It is soluble in excess of KCN, due to formation of the following complex : -

asked Jul 23, 2018 by pady_1

1 answer

Which of the following two species in the pair are isostructural :-

asked Jul 20, 2018 by pady_1

2 answers

Isoelectronic species are :

asked Jul 20, 2018 by pady_1

1 answer

Which of the following gives colour with the water :

asked Jun 15, 2018 by pady_1

1 answer

A woman introduces a man as the son of the brother of her mother. How is the man related to the woman?

asked Dec 31, 2015 by pady_1

1 answer

In 2008 approximately what percent of the world's population lived in Africa?

asked Dec 31, 2015 by pady_1

1 answer

Find the area of a rectangle of length 15 mm and breadth 7 mm.

asked Dec 31, 2015 by pady_1

1 answer

Convert the following to a mixed fraction : $\large\frac{75}{12}$

asked Dec 31, 2015 by pady_1

1 answer

Brody had 21 green marbles. Then he bought 9 bags of blue marbles. There were 5 marbles in each bag. How many marbles does Brody have now?

asked Dec 31, 2015 by pady_1

0 answers

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