Below are the 30 Most Important chemistry MCQs for competition Exams 2024:
Fundamentals of Chemistry MCQs Part Two:
1➤ What is the symbol of Magnesium?
ⓑ Mg
ⓒ Au
ⓓ Zn
2➤ A group of atoms that has some charge is called a:
ⓑ Valency
ⓒ Radical
ⓓ Duplet
3➤ Elements with more than four electrons in last shell prefer to octet. electrons to complete
ⓑ Share
ⓒ Gain
ⓓ Penetrate
4➤ Chlorine and bromine have seven electrons in their shell and show a valency of:
ⓑ -2
ⓒ +1
ⓓ +3
5➤ In which of the following compounds, iron has the valency of +2?
ⓑ FeCl3
ⓒ Fe2(SO4)3
ⓓ Fe3(PO4)3
6➤ When two or more elements chemically combine in a fixed mass ration, the new substance formed is known as:
ⓑ Element
ⓒ Radical
ⓓ Compound
7➤ While making a compound, the combining elements lose their properties forming a new substance with completely----------properties.
ⓑ Alike
ⓒ Different
ⓓ Similar
8➤ What is the fixed mass ratio of hydrogen and oxygen in water?
ⓑ 1:16
ⓒ 2:8
ⓓ 16:1
9➤ Compounds in which ions join in three dimensions forming crystal lattice are called-------------compounds.
ⓑ Covalent
ⓒ Coordinate Covalent
ⓓ None
10➤ Which of the following is a covalent compound?
ⓑ CuSO4
ⓒ CaCl₂
ⓓ NH3
11➤ When two or more elements or compounds are mixed physically without any fixed ratio, they form a:
ⓑ Mixture
ⓒ Radical
ⓓ Ion
12➤ Which of the following is a homogenous mixture?
ⓑ Sand
ⓒ Soil
ⓓ Wood
13➤ The number of protons present in the nucleus of an atom is called its:
ⓑ Mass number
ⓒ Atomic mass
ⓓ Atomic weight
14➤ What is the number of neutrons in an atom when its A = 24 and Z = 12?
ⓑ 11
ⓒ 9
ⓓ 8
15➤ The average mass of an atom of 1 of an element as compared to 1/12 of the mass of carbon -12 atom is called is:
ⓑ Atomic number
ⓒ Mass number
ⓓ Proton number
16➤ 1 amu = ?
ⓑ 1.66x10-24g
ⓒ 11.7×10¹¹g
ⓓ 1.672x10-37g
17➤ While writing a chemical formula, valency number of each ion is written on---------corner of its symbol.
ⓑ Top right
ⓒ Bottom left
ⓓ Bottom right
18➤ Which of the following shows the elements present in a compound?
ⓑ Atomic number
ⓒ Relative atomic mass
ⓓ Chemical formula
19➤ The empirical formula of C6H12O6 is:
ⓑ CHO2
ⓒ C6H2O6
ⓓ CHO
20➤ The simplest unit that represents ionic compound and contains ions in simplest whole number is called as:
ⓑ Molecular formula
ⓒ Ionic formula
ⓓ Empirical formula
21➤ What is the molecular mass of H2SO4?
ⓑ 98 amu
ⓒ 118 amu
ⓓ 142 amu
22➤ An atom or a group of atoms having a positive or negative charge on it is called a/an:
ⓑ Element
ⓒ Formula
ⓓ Ion
23➤ A molecule is always:
ⓑ Positively Charged
ⓒ Negatively charged
ⓓ Unstable
24➤ How many moles are present in 49g of H3PO4?
ⓑ 0.408moles
ⓒ 5.8moles
ⓓ 4.8 moles
25➤ The smallest particle of an element or a covalent compound that can exist independently is called a/an:
ⓑ Compound
ⓒ Molecule
ⓓ Free radical
26➤ Formula mass of an --------- expressed in grams in called gram formula mass.
ⓑ Atom
ⓒ Ionic compound
ⓓ Molecule
27➤ What is the gram atomic mass of sodium?
ⓑ 24g
ⓒ 1.008g
ⓓ 98g
28➤ One mole is the amount of substance that contains-------- particles of its basic particles.
ⓑ 6.02x1023
ⓒ 6.91×1017
ⓓ 6.01x1024
29➤ What will be the number of moles In 3.6 grams of water?
ⓑ 0.4 Moles
ⓒ 2 Moles
ⓓ 0.2 Moles
30➤ A positively charged ion is called:
ⓑ Cation
ⓒ Radical
ⓓ Element
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