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OTI365 - NTSE - X Standard
NTSE SAT Chemistry - Atoms and Molecules Practice Questions

SAT Chemistry - Atoms and Molecules

Exam Duration: 45 Mins Total Questions : 30

1 )

The number hydrogen atoms in 2 g of hydrogen is

(a)
2 x 6.022 x 10²³
(b)
6.022 x 10²³
(c)
2
(d)
1

2 )

What is the mass of 2 moles of HCI?

(a)
36.5 g
(b)
73 g
(c)
3.65 g
(d)
7.3 g

3 )

A solution is prepared by adding 109 of a substance to 40 g of water. The mass percent of the solute is

(a)
25%
(b)
10%
(c)
20%
(d)
40%

4 )

How many molecules are there in 0.1 moles of CO₂?

(a)
6.022 x 10²³
(b)
6.022 x 10²²
(c)
6.022 X 10²¹
(d)
6.022 X 10²⁴

5 )

The volume of 3.2 g oxygen gas at STP is

(a)
22.7 L
(b)
2.27 L
(c)
227 L
(d)
0.227 L

6 )

The symbols for ferric ion and ammonium ion are respectively

(a)
Fe²⁺, NH₃
(b)
Fe²⁺, NH₄⁺
(c)
Fe³⁺, NH₄⁺
(d)
Fe³⁺, NH₂^-

7 )

Latin name of potassium is

(a)
Plumbum
(b)
Stannum
(c)
Natrium
(d)
Kalium

8 )

In which of the following pairs the magnitude positive charge of the cation is equal to the negative charge of the anion

(a)
Cupric ion and hydroxide ion
(b)
Ferrous ion and hydroxide ion
(c)
Cuprous ion and chloride ion
(d)
Ferrous ion and chloride ion

9 )

Which of the following is a trivalent ion?

(a)
Sulphide
(b)
Carbide
(c)
Oxide
(d)
Nitride

10 )

Molecular mass of nitrogen molecule is equal to the molecular mass of

(a)
NO
(b)
O₂
(c)
CO
(d)
None of these

11 )

The number of atoms per molecule is maximum in

(a)
Chlorine
(b)
Ozone
(c)
Argon
(d)
Hydrogen

12 )

The value of Avogadro number is

(a)
6.022 X 10²⁰
(b)
6.022 X .10²³
(c)
6.022 X 10²²
(d)
6.022 X 10²¹

13 )

Almost the entire mass of an atom is concentrated in the ____________

(a)
proton
(b)
electrons
(c)
nucleus
(d)
neutrons

14 )

An atom has a mass number of 23 and atomic number 11. The number of protons are ____________

(a)
11
(b)
12
(c)
23
(d)
24

15 )

The proton is heavier than an electron by ____________

(a)
1850 times
(b)
1840 times
(c)
1000 times
(d)
100 times

16 )

Carbon-12 atom has ______________

(a)
6 electrons, 6 protons, 6 neutrons
(b)
6 electrons, 12 protons, 6 neutrons
(c)
12 electrons, 6 protons, 6 neutrons
(d)
18 electrons, 6 protons and 6 neutron

17 )

In Rutherford's alpha-scattering experiment, a foil of element that was used _______

(a)
gold
(b)
silver
(c)
aluminium
(d)
magnesium

18 )

The quantity of matter present in an object is called its ___________

(a)
Mass
(b)
Volume
(c)
Density
(d)
Vapour pressure

19 )

Avogadro number represents the number of atoms in ___________

(a)
12 grams of 12C
(b)
3320 grams of sulphur
(c)
32 grams of oxygen
(d)
1 gram of 12C

20 )

2 molecules of nitrogen are represented by ____________.

(a)
N
(b)
2N₂
(c)
N₂
(d)
2N

21 )

One mole of H₂O corresponds to:

(a)
22.4 litre at 1 atm and 25°C
(b)
6.02 x 10²³ atoms of hydrogen and 6.02 x 10²³ atoms of oxygen
(c)
18 g
(d)
1 g

22 )

Which postulate of Dalton's Atomic theory suggests the law of conservation of mass

(a)
Atoms cannot be divided
(b)
All the meter is made up of very small particles called atoms
(c)
Elements consist of atoms combined in a fixed ratio
(d)
Atom can neither be created nor be destroyed.

23 )

When 5 g of Calcium is burnt in 2 g of Oxygen then 7 g of Calcium oxide is produced. What mass of calcium oxide will be produced when 5 g of calcium reacts with 20 g of oxygen?

(a)
7g
(b)
2g
(c)
25g
(d)
4g

24 )

Hydrogen & 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

25 )

The symbol of element oxygen is

(a)
O
(b)
O₂
(c)
O₃
(d)
None of these

26 )

The first scientist to use the symbols of elements was

(a)
Dalton
(b)
Berzilius
(c)
Kanad
(d)
Proust

27 )

Which of the following represents a polyatomic ion

(a)
Sulphide
(b)
Chloride
(c)
Sulphate
(d)
Nitride

28 )

Two elements A (atm wt 75) and B (atm wt. 165) combine to yield a compound.the percentage by weight of A in the compound was found to be 75.08.The formula of the compound is