Chemistry NTSE

CAREER POINT

PRE FOUNDATION DIVISION

SUMMER WORKSHOP (NTSE)

Daily Practice Problem Sheet

Subject : Chemistry Topic : Atoms & Molecules DPPS. NO. – 01.

OBJECTIVE TYPE QUESTIONS :

Q.1 Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas ?

(A) 24 g (B) 27 g (C) 21 g (D) 3 g

Q.2 _{Amount of BaSO4 formed on mixing the aqueous solutions of 2.08 g BaCl2 and excess of dil. H2SO4 is} [atomic weights : Ba = 137, Cl = 35.5, S = 32, O = 16].

(A) 2.33 g (B) 2.08 g (C) 1.04 g (D) 1.165 g

Q.3 Percentage of copper and oxygen in sample of CuO obtained by different methods were found to be same. This proves the law of :

(A) constant proportion (B) multiple proportion (C) reciprocal proportion (D) None

Q.4 A gaseous mixture contains oxygen and nitrogen in the ratio of 1:4 by mass. Therefore, the ratio of their number of molecules is

-(A) 1 : 4 (B) 1 : 8 (C) 7 : 32 (D) 3 : 16 Q.5 Law of multiple proportion is not obeyed by

-(A) oxide of phosphorus (B) oxide of nitrogen (C) oxide of aluminium (D) oxide of carbon

Q.6 At same temperature and pressure equal volumes of two or more gases have the equal number of atoms. Above hypothesis was given by

-(A) Avogadro (B) Dalton

(C) Gay-lussac (D) None of these Q.7 1 u is equal to

-Q.13 _{In a compound AxBy}

-(A) Mole of A = Mole of B = mole of AxBy (B) Eq. of A = Eq. of B = Eq. of AxBy

(C) X × mole of A = y × mole of B = (x + y) × mole of AxBy (D) X × mole of A = y × mole of B

Q.14 _{8g of sulphur are burnt to form SO2, which is oxidised by Cl2 water. The solution is treated with BaCl2} solution. The amount of BaSO4 precipitated is

-(A) 1.0 mole (B) 0.5 mole

(C) 0.75 mole (D) 0.25 mole Q.15 No. of oxalic acid molecules in 100 mL of 0.02 N oxalic acid are

-(A) 6.023 × 1020 (B) 6.023 × 1021 (C) 6.023 × 1022 (D) 6.023 × 1023 Q.16 How much water is to be added to dilute 10 mL of 10 N HCl to make it decinormal ?

(A) 990 mL (B) 1010 mL (C) 100 mL (D) 1000 mL Q.17 Insulin contains 3.4% sulphur. The minimum molecular weight of insulin is

-(A) 941.176 u (B) 944 u

(C) 945.27 u (D) None of these Q.18 _{Weight of oxygen in Fe2O3 and FeO is in the simple ratio of}

-(A) 3 : 2 (B) 1 : 2 (C) 2 : 1 (D) 3 : 1 Q.19 _{The mole fraction of water in 20% (wt. /wt.) aqueous solution of H2O2 is}

-(A) 68 77 (B) 77 68 (C) 80 20 (D) 20 80

Q.20 _{100 ml of 0.5 N NaOH were added to 20 ml of 1.N HCl and 10 ml of 3 N H2SO4. The solution is} -(A) acidic (B) basic (C) neutral (D) none of these

CAREER POINT

PRE FOUNDATION DIVISION

SUMMER WORKSHOP (NTSE)

Daily Practice Problem Sheet

Subject : Chemistry Topic : Structure of Atom DPPS. NO. – 02.

OBJECTIVE TYPE QUESTIONS : Q.1 Faraday’s Dark space refers to

-(A) Dark space in the nucleus (B) Dark space in the atom

(C) Dark space in between the cathode and positive column (D) Dark space between the cathode & cathode glow Q.2 In an atom, M shell can occupy maximum

of-(A) 2 electrons (B) 8 electrons (C) 18 electrons (D) 32 electrons

Q.3 The atomic number and atomic mass of an element ‘E’ are 53 and 127 respectively. The number of neutrons present in one atom of ‘E’ is :

(A) 53 (B) 74 (C) 280 (D) 37

Q.4 Which of the following has a same number of protons, electrons & neutrons ?

(A) 54₂₇X (B) 55₂₇X1 (C) 54₂₆X (D) 55₂₈X

Q.5 Element ‘A’ with general outer shell configuration ns2np5 usually exists as

-(A) A and forms A¯ ion. (B) A and forms A+ ion. (C) A2 and forms A¯ ion. (D) A2 and forms A–2 ion. Q.6 The ratio of e/m for a cathode ray

-(A) varies with a gas in a discharge tube (B) is fixed

(C) varies with different electrodes (D) is maximum if hydrogen is taken

Q.7 Atoms may be regarded as comprising of protons, neutrons and electrons. If the mass attributed by electrons was doubled and that attributed by neutrons was halved, the atomic mass of 12C would be

-Q.13 An atomic orbit can contain a maximum number of electron according to Bohr Bury, which is given by

-(A) 2n2 (B) n2 (C) (n–1)2 (D) 3n2

Q.14 Which of the following has maximum number of unpaired electrons.

(A) Cu+2 (B) Cr+3 (C) Ni+2 (D) Fe+3

Q.15 The principal quantum number n can have integral values

-(A) 0 to 10 (B) 1 to (C) 1 to (n – 1) (D) 1 to 50 Q.16 For azimuthal quantum number  = 3 , the maximum number of electrons will be

-(A) 2 (B) 6 (C) 10 (D) 14

Q.17 Beryllium’s fourth electron will have the four quantum numbers.

n  m s (A) 1 0 0 – 2 1 (B) 1 1 1 + 2 1 (C) 2 0 0 – 2 1 (D) 2 1 0 + 2 1 Q.18 Nondirectional orbital is -(A) 3s (B) 4f (C) 4d (D) 4p

Q.19 The maximum number of electrons in a subshell is given by the expression

-(A) 4 + 2 (B) 4 – 2 (C) 2 + 1 (D) 2 µ2 Q.20 The maximum number of 3d electrons that can have s = +1/2 are

CAREER POINT

PRE FOUNDATION DIVISION

SUMMER WORKSHOP (NTSE)

Daily Practice Problem Sheet

Subject : Chemistry Topic : Periodic Classification of Elements DPPS. NO. – 03.

OBJECTIVE TYPE QUESTIONS :

Q.1 According to Newlands’ law of octaves 3rd element will resemble in its properties to

-(A) ninth element (B) eighth element (C) tenth element (D) eleventh element Q.2 Newlands could classify elements only upto

-(A) copper (B) chlorine (C) calcium (D) chromium

Q.3 Cl, Br,, if this is a Dobereiner’s triad and the atomic masses of Cl and are 35.5 and 127 respectively, then the atomic mass of Br is

-(A) 162.5 (B) 91.5 (C) 81.25 (D) 45.625 Q.4 In Lother Meyer’s curve most electronegative elements or halogens occupied

-(A) peaks (B) ascending positions (C) descending positions (D) halogens were not shown Q.5 In the long form of periodic table lanthanides are placed in the

-(A) 2nd period (B) 5th period (C) 6th period (D) 7th period Q.6 All the members in a group of long form of periodic table have the same

-(A) valency (B) number of valence electrons (C) chemical properties (D) All of these

Q.7 In the long form of periodic table, all the non-metals are placed

in-(A) s-block (B) p-block (C) d-block (D) f-block Q.8 In the modern periodic table which one of the following does not have appropriate position ?

(A) Transition elements (B) Inert gases (C) Inner transition elements (D) Halogens

Q.9 The element having electronic configuration [Kr]4d10 4f14 5s2 5p6 5d1 6s2 belongs to -(A) s-block (B) p-block (C) d-block (D) f-block Q.10 The correct order of second I.E. of C,N,O and F is

(C) Oxygen has high electron affinity

(D) O– ion has comparatively larger size than oxygen atom Q.15 Largest in size out of Na+, O–2 and K+ is

-(A) Na+ (B) O– 2 (C) K+ (D) all are equal Q.16 Electron affinity of X would be equal to

-(A) electron affinity of (B) ionisation potential of (C) ionisation potential of X (D) None of these Q.17 Which of the following have isoelectronic structures ?

(i) CH3+ (ii) H3O+ (iii) CH3– (iv) NH3

(A) (i), (ii) and (iii) (B) (i) and (iii) (C) (i) and (iv) (D) (ii),(iii) and (iv) Q.18 Which of the following ions has smallest radius ?

(A) Cl– (B) S2– (C) K+ (D) Ca2+

Q.19 The first ionisation energy of Na, Mg, Al and Si are in the order of -(A) Na < Mg > Al < Si (B) Na > Mg > Al > Si (C) Na < Mg < Al > Si (D) Na > Mg > Al < Si

Q.20 A sudden large jump between the values of second and third ionisation energies of an element would be associated with the electronic configuration

-(A) 1s2, 2s2 2p6,3s1 (B) 1s2, 2s2 2p6,3s2 3p1 (C) 1s2, 2s2 2p6,3s2 3p2 (D) 1s2, 2s2 2p6,3s2

CAREER POINT

PRE FOUNDATION DIVISION

SUMMER WORKSHOP (NTSE)

Daily Practice Problem Sheet

CHEMISTRY

ANSWER KEY

DPP-1 : Atoms & Molecules

Q.No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Ans. A A A C C D C D A A B C B D A A A D D C DPP-2 : Atomic Structure Q.No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Ans. C C B A C B C A A A C C A D B D C A A C DPP-3 : Periodic Classification Q.No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Ans. C C C B C D B C D D B B B A C B D D A D