The numbers 234,000 and 6.0012 can be represented in scientific notation as:
 

1. \(2.34 \times 10^{-9} \text { and } 6 \times 10^3\)
2. \(0.234 \times 10^{-6} \text { and } 60012 \times 10^{-9}\)
3. \(2.34 \times 10^{-9} \text { and } 6.0012 \times 10^{-9}\)
4. \(2.34 \times 10^5 \text { and } 6.0012 \times 10^0\)

Subtopic:  Introduction |
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The number of significant figures in the numbers 5005, 500.0, and 126,000 are, respectively: 
1. 2, 4, and 3 
2. 4, 1, and 3 
3. 4, 4, and 6 
4. 4, 4, and 3 
Subtopic:  Introduction |
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Level 3: 35%-60%

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The correct match is:
List-I List-II
a. Micro i.  10-15 m
b. Mega ii.  10-6 m
c. Giga iii.  106 m
d. Femto iv.  109 m
Codes:
a b c d
1. i iv iii ii
2. iii iv ii i
3. ii iii iv i
4. i iii iv ii
Subtopic:  Introduction |
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How many grams of HCl are required to react with 5.0 g of manganese dioxide in the reaction provided?
\(4 \mathrm{HCl}_{(\mathrm{aq})}+\mathrm{MnO}_{2(\mathrm{~s})} \rightarrow 2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}+\mathrm{MnCl}_{2(\mathrm{aq})}+\mathrm{Cl}_{2(\mathrm{~g})}\)


1. 4.8 g

2. 6.4 g

3. 2.8 g

4. 8.4 g

Subtopic:  Equation Based Problem |
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Level 2: 60%+

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The molar mass of naturally occurring Argon isotopes is: 

Isotope Isotopic molar mass Abundance
36-Ar  35.96755 g mol–1 0.337%
38-Ar  37.96272 g mol–1  0.063%
40-Ar  39.9624 g mol–1  99.600%
 
1. 49.99947 g mol-1  2. 39.99947 g mol-1  
3. 35.59947 g mol-1   4. 45.59947 g mol-1  
Subtopic:  Empirical & Molecular Formula |
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Level 1: 80%+

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If 10 volumes of H₂ react completely with 5 volumes of O₂, what volume of water vapor will be produced under the same conditions of temperature and pressure?

1. 9

2. 8

3. 10

4. 11

Subtopic:  Equation Based Problem |
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In a reaction A + B2 → AB2, 
A will act as a limiting reagent if :

i. 300 atoms of A reacts with 200 molecules of B
ii. 2 moles A reacts with 3 moles B2
iii. 100 atoms of A reacts with 100 molecules of B
iv. 5 moles A reacts with 2.5 moles B
v. 2.5 moles A reacts with 5 moles B2

 
Choose the correct option:

1. (i), (ii) 2. (i), (ii), (v)
3. (ii), (v) 4. All
Subtopic:  Limiting Reagent |
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Level 2: 60%+

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Calculate the mass percentages of sodium (Na), sulfur (S), and oxygen (O), respectively, in sodium sulphate (Na₂SO₄):

1. 32.4%, 45.05% and 22.6%

2. 22.6%, 45.05% and 32.4%

3. 32.4%, 22.6% and 45.05%

4. 45.05%, 32.4% and 22.6%

Subtopic:  Introduction |
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Given below are two statements:
Assertion (A): When 4 moles of H2 reacts with 2 moles of O2, then 4 moles of water are formed.
Reason (R): O2 will act as a limiting reagent.
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. Both (A) and (R) are False.
Subtopic:  Equation Based Problem |
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Level 3: 35%-60%

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Assertion (A): The number of molecules in 2 moles of NH3 is equal to the number of molecules in 4 moles of CH4.
Reason (R): Both are chemically similar species.
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. Both (A) and (R) are False.
Subtopic:  Moles, Atoms & Electrons |
 82%
Level 1: 80%+

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