Chemistry Practice Questions

Question

A mixture of carbonates of two bivalent metals contains 13.6% of one metal. If 2.5 g of the mixture liberates 1.33 g CO_2 , the % by weight of the other metal is

Possible Answers

Selected	Possible Answer
	12
	13.44
	113.6
	15

Question

A pyrolusite sample containing 80% MnO_2 will oxidise the same amount of oxalic acid as 37.12 ml of parmagnate solution , of which 1.0 ml will liberate 0.0175 g of I_2 from . The mass of the

Possible Answers

Selected	Possible Answer
	2.78 g
	1.278
	0.278 g
	27.8 g

Question

$N_2 + 3H_2 \rightarrow 2NH_3$
Molecular weight of NH_3

and

are

and

, their equivalent weight are E_1

and

. Then

is

Possible Answers

Selected	Possible Answer
	$\Big ( \cfrac{2m_1 - m_2}{6}\Big )$

Question

The number of moles of $Cr_2O_7 ^{-2}$ needed to oxidise 0.136 equivalents of N_2H_5 ^+

by the reaction

$N_2H_5 ^{+} + Cr_2O_7 ^{-2}\rightarrow N_2 + Cr^{+3} + H_2O$ is

Possible Answers

Selected	Possible Answer
	0.816
	0.136
	0.0227
	0.272

Question

40 ml of 0.05 M solution of sodium sesquicarbonate (Na_2CO_3. NaHCO_3.2H_2O) is titrated against 0.05 M HCl . x ml of HCl is used when phenolphthalein is the indicator and y ml of HCl is used when methyl orange is the indicator in two separate titration. Hence (y-x) is

Possible Answers

Selected	Possible Answer
	30 ml
	80 ml
	180 ml
	120 ml

Question

A potassium salt has the formula

H_2C_2O_4. KHC_2O_4. XH_2O

1.923 g of the salt is neutralised by 22.7 cm^3

of 1M

using phenophthale in indicator, what is the value of x

Possible Answers

Selected	Possible Answer
	1
	4
	2
	8

Question

$7.65 * 10^{-3}$ moles of NaNO_3

require $3.06 * 10^{-2}$ moles of a reducing agent to get reduced to NH_3

. What is the n-factor of the reducing agent

Possible Answers

Selected	Possible Answer
	5
	2
	3
	4

Question

0.36 g of Iron Pyrites is heated strongly in air. The SO_2 thus produced is passed through acidified K_2Cr_2O_7 solution. The moles of acidified solution used in redox titration

Possible Answers

Selected	Possible Answer
	None of these
	20
	10
	30

Question

In an experiment, 50 ml of 0.1 M solution of a metallic salt reacted exactly with 25 ml of 0.5 M solution of sodium sulphite. In the reaction $SO_3 ^{2}$ oxidised to $SO_4 ^{-2}$ , if the original oxidation number of metal in the salt was 3, what would be the new oxidation number of the metal

Possible Answers

Selected	Possible Answer
	2
	4
	0
	1

Question

What weight of HNO_3

is needed to convert 5 g of iodine into iodic acid according to the reaction

$I_2 + HNO_3 \rightarrow HIO_3 ^+ NO_2 + H_2O$

Possible Answers

Selected	Possible Answer
	24.8 g
	49.6 g
	0.248 g
	12.4 g

Question

An aqueous solution containing 0.10 g KIO_3 (Formula wt. = 214) and an excess of KI was acidified with HCl. The liberated I_2 consumed 45.0 ml of thiosulphate the molarity of sodium thiosulphate.

Possible Answers

Selected	Possible Answer

Question

22.4 litres of H_2S and 22.4 litres of SO_2 both at S.T.P. are mixed together. The amount of sulphur precipitated as a result of chemical calculation is

Possible Answers

Selected	Possible Answer
	23 g
	48 g
	96 g
	16 g

Question

One litre of CO_2 is passed over hot coke. The volume becomes 1.4 litre. The percentage composition of product is

Possible Answers

Selected	Possible Answer
	None
	0.8 litre
	0.6 litre
	0.6 litre and 0.8 litre

Question

In the gaseous reaction of the type $aA + bB \rightarrow cC + dD$ which is wrong

Possible Answers

Selected	Possible Answer
	a g of A combines with b g of B to give C
	a mole of A combines with b moles of B to give C and
	a molecuels of A combines with b molecules of B to vive C and D
	a litre of A combines with b litre of B to give C and D

Question

Rutherford’s scattering formula fails for very small scattering angles because

Possible Answers

Selected	Possible Answer
	The impact parameter between the $\alpha$ -particle source and the nucleus of the target is very large compared to the size of the nucleus
	The gold foil is very thin
	The kinetic energy of the $\alpha=$ particle is large
	The full nuclear charge of the target atom is completely screened by its electron

Question

For an electron in a hydrogen atom, the wave function, $\psi$ is proportional to ext - (r/a_0) , where a_0 is the Bohr’s radius. What is the ratio of the probability of finding the electron at the nucleus to the probability of finding it at a_0

Possible Answers

Selected	Possible Answer

Question

Suppose $10^{-17}$ J of energy is needed by the interior of human eye to see an object. How many photons of green light ( $\lambda = 550 nm$ ) are needed to generate this minimum amount of energy

Possible Answers

Selected	Possible Answer
	28
	39
	42
	14

Question

Which of the following parameters are the same for all hydrogen –like atoms and ions in their ground states

Possible Answers

Selected	Possible Answer
	speed of the electron
	radius of the orbit
	energy of the atom
	orbital angular momentum of the electron

Question

Difference between nth and (n+1)th Bohr’s radius of ‘H’ atom is equal to it’s (n-1)th Bohr’s radius. The value of n is

Possible Answers

Selected	Possible Answer
	1
	3
	4
	2

Question

Three photons coming from excited atomic hydrogen sample are picked up. Their energies are ‘2.1 eV, 10.2 eV and 1.9 eV. These photons must come from

Possible Answers

Selected	Possible Answer
	a single atom
	three atoms
	two atoms
	either two atoms or three atoms

Question

Spin of electron is

Possible Answers

Selected	Possible Answer
	rotation of electron about it’s own axis
	clockwise and anticlockwise rotation of electron
	an intrinsic characteristic of electron connected with its magnetic field
	a quantum number which depend upon direction and speed of rotation of electron

Question

The wavelength associated with a golf ball weighting 200 g and moving with a speed of 5 m/h is of the order of

Possible Answers

Selected	Possible Answer
	$10^{-20} m$
	$10^{-40}m$
	$10^{-10} m$
	$10^{-30}m$

Question

The quantum numbers +1/2 and –1/2 for the electron spin represent

Possible Answers

Selected	Possible Answer
	Rotation of the electron in clockwise and anticlockwise direction respectively
	Rotation of the electron in anticlockwise and clockwise direction respectively
	Magnetic moment of the electron pointing up and down respectively
	Two quantum mechanical spin states, which have no classifical analogue

Question

Which of the following statements are correct

A – All substances have magnetic properties

B – There are substances in which all electrons spins are paired

C – There are substances in which one or more electrons have un paired spins

D – The greater the number of unpaired electrons, the greater the paramagnetism per mole of substance

Possible Answers

Selected	Possible Answer
	CD
	ABCD
	AB
	DA

Question

A radioactive isotope x with half life of 1.37 * 10^9 years decays to y which is stable. A sample of rock from the moon was found to contain both the elements x and y in the ratio 1:7. What is the age of the rock

Possible Answers

Selected	Possible Answer
	years

Question

A radioactive mixture containing a short-lived species A and a long-lived species B. Both emitting $\alpha$ -particles at a given instant emits at rest, 10,000 $\alpha$ -particles per minute. 10 minutes later it emits at the rate of 7000 particles per minute. If the half lives of the species are 10 min and 100 hrs respectively then the ratio of activities of A:B in the initial mixture was

Possible Answers

Selected	Possible Answer
	6:4
	None of above
	4:6
	3 : 7

Question

The probability of survival of a radioactive nucleus for one mean life is

Possible Answers

Selected	Possible Answer
	$\Big ( 1-\frac{In2}{e}\Big )$
	$\cfrac{1}{e}$
	In $\frac{(2)}{e}$
	$\Big ( 1-\frac{1}{e}\Big )$

Question

Half life of a radioactive substance A is 2 times the half life of another radioactive substance B. Initially the number of nuclei of A and B are N_A and N_B respectively. After three half lives of A, number of nuclei of both becomes equal, the ratio $\cfrac{N_A}{N_B}$ is

Possible Answers

Selected	Possible Answer
	$\cfrac{1}{6}$
	$\cfrac{1}{3}$
	$\cfrac{1}{4}$
	$\cfrac{1}{8}$

Question

At radioactive equilibrium, the ratio between the atoms of two radioactive elements A and B was found to be 3.1 * 10^9 : 1 respectively. If $T_{50}$ of the element A is $2* 10^{10}$ years, then $T_{50}$ of the element B is

Possible Answers

Selected	Possible Answer

	None
	$3*10^8 \; years$
	$6.45 \; years$

Question

Energy released in the process [B.F per nucleon of, H^2

and

and

are 1.1MeV & to MeV respectively

$_1H^2 + _1H^2 \rightarrow _2He^4$ is

Possible Answers

Selected	Possible Answer
	25.2 MeV
	16.6 MeV
	20.8 MeV
	23.6 MeV

Question

$\overset{27}{13}$ Al is stable isotope, $\overset{29}{13}$ Al is expected to disintegrated by

Possible Answers

Selected	Possible Answer
	neutron emission
	$\alpha - emission$
	positron emission
	$\beta - emission$

Question

Which among the following is wrong about isodiaphers?

Possible Answers

Selected	Possible Answer
	Nucleide and its decay product after $\alpha$ -emission are isodiaphers
	They have the same difference of neutrons and protons or same isotopic number
	All correct
	$zA^m \rightarrow z - 2B^{m-4} + _2He^4$

Question

Among the following nucledes, the highest binding energy per nucleon is found for

Possible Answers

Selected	Possible Answer

	$_8O^{16}$
	$_{26}Fe^{56}$
	$_{92}U^{235}$

Question

The number of peroxide linkages in CrO_5 are

Possible Answers

Selected	Possible Answer
	Two
	One
	None
	Three

Question

The molecule which has T-shaped structure is

Possible Answers

Selected	Possible Answer

Question

In solid phase, PBr_5 exists as

Possible Answers

Selected	Possible Answer

	$PBr_4 ^{+} , Br^{-}$

	$PBr_4 ^{+}$ , $PBr_6 ^{-}$

Question

Which of the following halogen has highest bond dissociation energy

Possible Answers

Selected	Possible Answer
	F-F
	Br –Br
	Cl – Cl
	I – I

Question

Structure of XeO_2F_2 is

Possible Answers

Selected	Possible Answer
	tetrahedra
	distorted tetrahedral
	square planar
	triangular planar

Question

The correct order of increasing C-O bond length of , $CO_3 ^{-2}$ and CO_2 is

Possible Answers

Selected	Possible Answer
	$CO< CO_3 ^{-2} < CO_2$
	$CO<CO_2 < CO_3 ^{-2}$
	$CO_3 ^{-2} <CO_2 < CO$
	$CO_2 < CO_3 ^{-2} < CO$

Question

Which of the following species have undistorted octahedral structures?

$A. \quad SF_6$

$B. \quad PF_6 ^{-}$

$C. \quad S_iF_6 ^{-2}$

$D. \quad XeF_6$

Possible Answers

Selected	Possible Answer
	AB
	ABC
	BDC
	ABD

Question

In which excited state iodine shows sp^3d^3 hybridisation state

Possible Answers

Selected	Possible Answer
	third
	zero
	second
	fist

Question

Formation of which of the following anion is not possible

Possible Answers

Selected	Possible Answer
	$[AlF_6]^{3-}$
	$[BF_6]^{3-}$
	$[SiF_6]^{2-}$
	$[BF_4]^{-}$

Question

There are four molecules $CO_2, N_3 ^{-}$ , $\overset{+}{N}O_2$ and $I_3 ^{-2}$ . Which of the following is correct about these molecules

Possible Answers

Selected	Possible Answer
	, $N_3 ^{-}$ , $\overset{+}{N}O_2$ are linear but $I_3 ^{-}$ is not
	all are linear but only , $N_3 ^{-}$ and $\overset{+}{N}O_2$ have sp hybridization on their central atom
	all are linear and having sp hybridization of central atoms
	all are linear but only and $N_3 ^{-}$ have sp hybridization on their central atom

Question

If one assumes linear structure instead of bent structure for water, then which one of the following properties cannot be explained?

Possible Answers

Selected	Possible Answer
	the high boiling point of water
	solubility of polar compounds in water
	ability of water to form co-ordinate covalent bond
	the formation of intermolecular hydrogen bond in water

Question

Main axis of a diatomic molecule is z, molecular orbital p_x and p_y overlap to form, which of the following orbital

Possible Answers

Selected	Possible Answer
	$\delta$ molecular orbital
	$\sigma$ molecular orbital
	$\pi$ molecular orbital
	no bond will

Question

The correct order of dipole moment is

Possible Answers

Selected	Possible Answer

Question

The common features among the species $CN^{-}$ , and NO^+ are

Possible Answers

Selected	Possible Answer
	bond order three and iso electronic
	bond order three and weak field ligands
	bond order two and $\pi$ -acceptors
	iso electronic and weak field ligands

Question

Molecular structure of SF_4 , CF_4 and XeF_4 are

Possible Answers

Selected	Possible Answer
	different with 1.0 and 2 lane pairs of electrons respectively
	the same, with 1,1 and 1 lone pairs of electrons respectively
	different, with 0, 1 and 2 lone pairs of electrons respectively
	the same, with 2, 0 and I lone pairs of electrons respectively

Question

How many mole of electrons are involved in the reduction of one mole of $MnO_4 ^{-}$ ion in alkaline medium to $MnO_{4} ^{2-}$

Possible Answers

Selected	Possible Answer
	4
	3
	2
	1

Question

The two sulphur atoms in Na_2S_2O_3 have

Possible Answers

Selected	Possible Answer
	+4 and +6 oxidation state
	-2 and +6 oxidation state
	same oxidation state
	+2 and + 4 oxidation state

Question

The oxidation state of oxygen in O_2 Pt F_7

Possible Answers

Selected	Possible Answer
	$+\frac{1}{2}$
	$-\cfrac{1}{2}$

Question

A 2.5 mole of hydrazine (N_2H_4) loses 25 mole of electrons in being converted to a new compound X. Assuming that all of these nitrogen appear in the new compound, what is the oxidation state of nitrogen in compounds X.

Possible Answers

Selected	Possible Answer
	–2
	-1
	+3
	+ 4

Question

In the presence of $H^{\oplus}$ ions, which of the following species can act as very strong oxidising agent

Possible Answers

Selected	Possible Answer
	All
	$CIO_4 ^{-}$
	$CIO_3 ^{-}$
	$CIO^{-}$

Question

Which of the following statements is /are correct

A – Oxyanions are stronger oxidizing agents in acidic than in neutral or basic solution

B – Oxyanions can be reduced to a variety of species depending upon the experimental conditions

C – $CrO_4 ^{2-}$ ions is stable in basic solution

D – None is correct

Possible Answers

Selected	Possible Answer
	CB
	BCD
	DAB
	ABC

Question

How many moles of nitrogen is produced by the oxidation of one mole of hydrazine by $\frac{2}{3}$ mole bromate ion

Possible Answers

Selected	Possible Answer
	$\frac{1}{3}$

	$\frac{2}{3}$

Question

Which of the following acids are likely to form Z witterions

A –

B –

C –

D –

Possible Answers

Selected	Possible Answer
	ABCD
	C
	BD
	D

Question

The set with correct order of acidity is

Possible Answers

Selected	Possible Answer

Question

The conjugate base of [Al (H_2O)_3(OH)_3] is

Possible Answers

Selected	Possible Answer
	$[Al (H_2O)_3(OH_2)O^{-}]$

	$[Al(H_2O)_2 (OH_4]^{-}$
	$[Al (H_2O)_3(OH)_3]^{-}$

Question

Which is the decreasing order strength of the bases $OH^{-}$ , $NH_2 ^{-}$ $H - C \equiv C^{-}$ and $CH_3CH_2 ^{-}$

Possible Answers

Selected	Possible Answer
	$CH_3CH_2 ^{-} > NH_2 ^{-} > H - C \equiv C^{-} > OH^{-}$
	$NH_2 ^{-7} H-C \equiv C^{-}OH^{-} > OH^{-} >CH_3CH_2 ^{-}$
	$H-C \equiv C^{-} > CH_3CH_2 ^{-} > NH_2 ^{-} > OH^{-}$
	$OH^{-} > NH_2 ^{-} > H - C \equiv C^{-} > CH_3CH_2 ^{-}$

Question

Which one of the following is the correct order of basic strength.

Possible Answers

Selected	Possible Answer

Question

Which of the following has been arranged correctly in increasing order of acid strength.

A – HF < HCl < HBr < HI

B – H_3PO_2 < H_3PO_3 < H_3PO_4

C – H_3 PO_4 > H_2SO_4 > HCIO_4

D – NH_3 < PH_3 < AsH_3 < BiH_3

Possible Answers

Selected	Possible Answer
	C
	AD
	D
	CD

Question

Which of the following has been arranged in increasing order of acidic strength

Possible Answers

Selected	Possible Answer

Question

Which of the following salts are acidic in aqueous solutions

A – (NH_4)_2SO_4

B – NaHCO_3

C – CuSO_4

D – AgNO_3

Possible Answers

Selected	Possible Answer
	ACD
	DAB
	D
	BCD

Question

Among the following which is the strongest protonic acid

Possible Answers

Selected	Possible Answer

Question

Among the following which is the strongest protonic acid

Possible Answers

Selected	Possible Answer


	$Fe(H_2O)_6]^{2+}$
	$[Fe(H_2O)_6]^{3+}$

Question

Which of the following is the correct order of basic nature of the compounds

Possible Answers

Selected	Possible Answer
	IV > III > I > III
	None
	I > II > III> VI
	III > I > IV > II

Question

Which of the following is the correct order of basic nature of the compounds.

Possible Answers

Selected	Possible Answer
	III > I > IV > II
	I > III > II > IV
	IV > I > III > II
	II > IV > I > III

Question

Arrange m-methoxy phenol (A). o- methoxy phenol (B), p- methoxy phenol© and phenol (D) in order or decreasing acid strength

Possible Answers

Selected	Possible Answer
	A > D > B > C
	A > B >C > D
	D > A >C > B
	A > D > C> D

Question

The decreasing order of basic character of the amines and ammonia is

Possible Answers

Selected	Possible Answer

Question

$Mg^{2+}$ is …......... than $Al^{+3}$

Possible Answers

Selected	Possible Answer
	Weaker Lewis base
	Stronger Lewis base
	Weaker Lewis acid
	Stronger Lewis acid

Question

I. II, III are three isotherms respectively at T_1 T_2 and T_3 . Temperature will be in order

Possible Answers

Selected	Possible Answer

Question

The vander Waals’ equation is $\Big ( p+\frac{n_2 a}{V}\Big )$ (V-nb)= nRT for n moles where a and b are vander Waal’s constant which of the following statements are true about a and b when the temperature of the gas is too low

Possible Answers

Selected	Possible Answer
	a varies , b remains same
	both remains same
	a remains same , b varies
	both varies

Question

The circulation of blood in human body supplies O_2 and releases CO_2 . The concentration of O_2 and CO_2 is variable but on the average, 100 ml blood contains 0.02 g of O_2 and 0.08 g of CO_2 . Calculate the volume of O_2 and CO_2 at 1 atm and body temperature 37^0 C , assuming 10 litre blood in human body

Possible Answers

Selected	Possible Answer
	2 litre , 4 litre
	1.5 litre , 4.5 litre
	1.59 litre , 4.62 litre
	3.82 litre , 4.62 litre

Question

The tube in the fig. is Shielded at both end and is heated up to double the original temperature both side of Hg column gases are packed with increasing temperature the Hg column

Possible Answers

Selected	Possible Answer
	Start to vibrate
	Shift towards ‘A’
	Shift towards ‘B’
	Remains same

Question

When an ideal gas undergoes unrestricted expansion, on cooling takes place because the molecules

Possible Answers

Selected	Possible Answer
	Are above the inversion temperatures
	Exert no attractive forces
	Collide without loss of energy
	Do work equal to loss of KE

Question

A closed vessel is maintained at a constant temperature it is first evacuated , and then an ideal gas is introduced into it continuously. The pressure of the gas inside the vessel will

Possible Answers

Selected	Possible Answer
	make it burst after some time
	first increases and then remains constant
	first increases and then decrease
	remains constant

Question

For two gases, A and B with molecular weights M_A and M_B , it is observed that at a certain temperature T, the mean velocity of A is equal to the root mean square velocity of B. thus the mean velocity of A can be made equal to the mean velocity of B if

Possible Answers

Selected	Possible Answer
	Both A and B are placed at lower temperature
	A is at temperature T, and B at T’ and T’ .T > T
	Both A and B are raised to a higher temperature
	A is lowered to a temperature $T_2 = \frac{8}{3\pi}T$ . While B is at T

Question

The accompanying figure depicts the change in concentration of species A and B for the reaction $A \rightarrow B$ , as a function of time the point of intersection of the two curves represents

Possible Answers

Selected	Possible Answer
	$\operatorname{Data} \; insufficient\; \operatorname{to} \; predict$

Question

The first order decomposition reactions of N_2O_5

are written as

$2N_2O_5(g) \rightarrow 4NO_2(g) + O_2 (g)$ rate = K[N_2O_5]

$N_2O_5 (g) \rightarrow 2NO_2 (g) + \frac{1}{2}O_2 (g) \; rate = K'[N_2O_5]$

Which of the following fact is true

Possible Answers

Selected	Possible Answer

Question

A reaction, $X_2 + Y_2 \rightarrow 2XY$ occurs by the following mechanism

$X_2 \rightarrow X+ X$ ...................................(Slow)

$X +Y_2 \rightarrow XY + Y$ ..........................(Fast)

$X+Y \rightarrow XY$ ................................(Fast)

Its order would be

Possible Answers

Selected	Possible Answer
	2
	Zero
	1
	3/2

Question

Which of the following is correct graph for the reaction

Possible Answers

Selected	Possible Answer

Question

Following is the graph between log $T_{50}$ and log a (a = initial concentration) for given reaction at $27^\circ C$ . Hence order is

Possible Answers

Selected	Possible Answer
	3
	2
	0
	1

Question

For an exothermic chemical process occurring in two steps as

$A+B \overset{Slow}{\longrightarrow}$ $X \overset{Fast}{\longrightarrow} AB$

The progress of the reaction can be best described by

Possible Answers

Selected	Possible Answer



	None of these

Question

A substance undergoes a first order decomposition. The decomposition follows two parallel first order reactions as

The percentage distribution of B and C are

Possible Answers

Selected	Possible Answer
	80% B, 20% C
	92% B, 8% C
	68% B, 32 % C
	76.83% B, 23 23.17%

Question

Two substance A(t_1/2 = 5 min) and B(t_1/2 = 15 min) . are taken in such away that initially [A] =4[B] . The time after which both the concentration will be equal is

Possible Answers

Selected	Possible Answer
	Concentration can never be equal
	5min
	15 min
	20 min

Question

For the reaction $N_2 + 3H_2 \rightleftharpoons 2 NH_3$ at 500^0 C

the value of K_p

is $1.44 *10^{-5}$ . What will be the value of
K_p

at low pressure where the gases are behaving almost ideally.

Possible Answers

Selected	Possible Answer
	$1.4410^{-5} (0.082* 500)^2$
	$1.44*10^{-5}$
	$1.4410^{-5} (0.082*773)^3$
	$(0.082 * 773)^2 * 1.44*10^{-5}$

Question

When chemical equilibrium is attained

Possible Answers

Selected	Possible Answer
	$\Delta G = 0$ and reaction quotient (Q) attains the maximum value called equilibrium constant (K) of the reaction
	$\Delta G = RT$ ln K
	$\Delta G^{\circ} = 0 \And Q = K$
	and Q assumes minimum value

Question

In a flask coloured N_2O_4 is in equilibrium with brown coloured NO_2 . At equilibrium when the flask is heated at $100^{\circ}C$ , the brown colour deepens and on cooling it becomes less coloured, the change in enthalpy, $\Delta H$ for the system is

Possible Answers

Selected	Possible Answer
	Zero
	Undefined
	Positive
	Negative

Question

Compare the acidity in terms of ratio of [H^+]

of 0.1

and 0.1

$K_a \quad for \quad CNO= 1.2 *10^{-4}$

and $K_a \quad for \quad HCN = 4 *10^{-10}$

Possible Answers

Selected	Possible Answer


	$3.025 * 10^{-5}$

Question

$_{79}Au$ (half-life 13.5 days) is $\beta$ -emitter forming $_{80}Hg$ . $_{80}Hg$ formed from 1g $_{79}Au$ after 54 days is

Possible Answers

Selected	Possible Answer
	$\frac{1}{16}$ g
	$\frac{1}{10}$ g
	$\frac{1}{4}$ g
	$\frac{15}{16}$ g

Question

A solution is mixture of 0.05 M NaCl

and 0.05 M Nal

. The concentration of I^-

ion in the solution when AgCl

just start to precipitating is equal to

$K_{sp}AgCl = 1*10^{-10} M^{2}$

$K_{sp} Agl = 1*10^{-16} M^2$

Possible Answers

Selected	Possible Answer
	$8*10^{-15}M$
	$2*10^{-7} M$
	$4*10^{-6} M$
	$2*10^{-8}M$

Question

The solubility of $C_6H_5NH_3 ^{+} Cl^{-}$ would be highest, among the following solvents in

Possible Answers

Selected	Possible Answer
	neutral buffer of pH = 7
	acidic buffer of pH = 3
	basic buffer of pH = 10
	pure water

Question

Which of the following acts as the best buffer

Possible Answers

Selected	Possible Answer
	$0.01 \; M \; CH_3CO_2H . 0.1 \; M CH_3CO_2Na$
	$0.1 \;M \; CH_3CO_2H . 0.01 \; M \; CH_3CO_2Na$
	$0.01\; M \; CH_3CO_2H. 0.01\; M \; CH_3CO_2 Na$
	$0.1 \; M \; CH_3CO_2H. 0.1\; M \; CH_3CO_2Na$

Question

Two buffer solution A and B each made with acetic acid and sodium acetate differ in their value of one unit . A has “salt acid = x: y” B has “ salt acid = x : y” x> y, then the value of x: y is

Possible Answers