Using the rules for significant figures, the correct answer for the expression \(\frac{0.02858 \times 0.112}{0.5702}\) will be :
1. \(0.005613\)
2. \(0.00561\)
3. \(0.0056\)
4. \(0.006\)

Subtopic:  Introduction |
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Consider the above reaction, the limiting reagent of the reaction and number of moles of NH3 formed respectively are:
1. \(\mathrm{H}_2, 1.42 \text { moles }\)
2. \(\mathrm{H}_2, 0.71 \text { moles }\)
3. \(\mathrm{N}_2, 1.42 \text { moles }\)
4. \(\mathrm{N}_2, 0.71 \text { moles }\)
Subtopic:  Moles, Atoms & Electrons |
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Compound A contains \(8.7\%\) Hydrogen, \(74\%\) Carbon and \(17.3\%\) Nitrogen. The molecular formula of the compound is:
(Given : Atomic masses of \(\mathrm{C, H}\) and \(\mathrm{N}\) are \(12, 1\) and \(14\) amu respectively. The molar mass of the compound A is \(\mathrm{162 ~g ~mol^{–1}}\))

1. \(\mathrm{C_4H_6N_2}\)
2. \(\mathrm{C_2H_3N}\)
3. \(\mathrm{C_5H_7N}\)
4. \(\mathrm{C_{10}H_{14}N_2}\)
Subtopic:  Empirical & Molecular Formula |
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Consider the reaction 
\(\small\begin{aligned} 4 \mathrm{HNO}_3(\mathrm{l}) +3 \mathrm{KCl}(\mathrm{s}) \ \rightarrow \mathrm{Cl}_2(\mathrm{~g})+\mathrm{NOCl}(\mathrm{g})+ \\2 \mathrm{H}_2 \mathrm{O}(\mathrm{g})+3 \mathrm{KNO}_3(\mathrm{~s}) \end{aligned}\)
The amount of HNO3 required to produce 110.0 g of KNO3 is: 
(Given: Atomic masses of H, O, N and K are 1, 16, 14 and 39 respectively).
1. 32.2 g
2. 69.4 g
3. 91.5 g
4.162.5 g
Subtopic:  Moles, Atoms & Electrons |
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On complete combustion of 0.492 g of an organic compound containing C, H and O, 0.7938 g of \(\mathrm{CO}_2\) and 0.4428 g of \(\mathrm{H}_ 2 \mathrm{O}\) was produced. The % composition of oxygen in the compound is:
1. 46% 2. 53%
3. 32% 4. 76%
Subtopic:  Empirical & Molecular Formula |
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A commercially sold conc. \(\text{HCl}\) is \(35\%\) \(\text{HCl}\) by mass. If the density of this commercial acid is \(1.46~\text{g/mL},\) the molarity of this solution is :
(Atomic mass: \(\text{Cl = 35.5 amu, H = 1 amu)}\)
1. \(10.2~\text{M}\)
2. \(12.5~\text{M}\)
3. \(14.0~\text{M}\)
4. \(18.2 ~\text{M}\)
Subtopic:  Concentration Based Problem |
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Two elements \(\mathrm{A}\) and \(\mathrm{B}\) which form \(0.15\) moles of \(\mathrm{A_2B}\) and \(\mathrm{AB_3}\) type compounds. If both \(\mathrm{A_2B}\) and \(\mathrm{AB_3}\) weigh equally, then the atomic weight of A is how many times that of B?

1. 8 times
2. 5 times
3. 3 times
4. 2 times

 
Subtopic:  Moles, Atoms & Electrons |
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The neutralization occurs when \(10~\text{mL}\) of \(0.1\text{M}\) acid ‘A’ is allowed to react with \(30~\text{mL}\) of \(0.05~\text{M}\) base \(\text{M(OH)}_2.\) The basicity of the acid ‘A’ is:
(M is a metal)
1. 1
2. 2
3. 3
4. 4
Subtopic:  Concentration Based Problem |
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Haemoglobin contains \(0.34\%\) of iron by mass. The number of \(\mathrm{Fe}\) atoms in \(\mathrm{3.3~g}\) of haemoglobin is: 
\(\small\mathrm{(Given : Atomic ~mass~ of ~Fe~ is~56 \mathrm{u}, \mathrm{N}_{\mathrm{A}}=6.022 \times\left.10^{23} \mathrm{~mol}^{-1}\right)}\)
1. \(1.21 \times 10^5 \)
2. \(12.0 \times 10^{16} \)
3. \(1.21 \times 10^{20} \)
4. \(3.4 \times 10^{22}\)
Subtopic:  Moles, Atoms & Electrons |
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\(120~\text{g}\) of an organic compound that contains only carbon and hydrogen gives \( 330~\text{g}\) of \(\text{CO}_2\) and \(270~\text{g}\) of water on complete combustion. The percentage of carbon and hydrogen, respectively are:
1. \(25\) and \(75\)
2. \(40\) and 60 
3. 60 and \(40\)
4. \(75\) and \(25\)
Subtopic:  Concentration Based Problem |
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