# 20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g of magnesium oxide. The percentage purity of magnesium carbonate in the sample will be:  (Atomic weight of Mg=24) 1. 75 2. 96 3. 60 4. 84

Subtopic:  Limiting Reagent |
64%
From NCERT
NEET - 2015
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What is the mass of precipitate formed when 50 mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8% NaCl solution? (Ag = 107.8, N = 14, O = 16, Na= 23, Cl = 35.5)
1. 28 g
2. 3.5 g
3. 7 g
4. 14 g

Subtopic:  Equation Based Problem |
54%
From NCERT
NEET - 2015
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Calculate  the mole fraction of the solute in a 1.00 m aqueous solution.

1. 0.177
2. 0.771
3. 0.0534
4. 0.0177

Subtopic:  Concentration Based Problem |
68%
From NCERT
NEET - 2015
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The number of water molecules is maximum in?

 1 18 molecules of water 2 1.8 g of water 3 18 g of water 4 18 moles of water
Subtopic:  Moles, Atoms & Electrons |
75%
From NCERT
NEET - 2015
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A mixture of gases contains H2 and O2 gases in the ratio of 1 : 4 (w/w). The molar ratio of the two gases in the mixture will be:

 1 1:4 2 4:1 3 16:1 4 2:1
Subtopic:  Moles, Atoms & Electrons |
70%
From NCERT
NEET - 2015
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When 22.4 litres of H2(g) is mixed with 11.2 litres of Cl2(g), both at STP, the moles of HCl(g) formed is equal to:

1. 1 mol of HCl(g)
2. 2 mol of HCl(g)
3. 0.5 mol of HCl(g)
4. 1.5 mol of HCl(g)

Subtopic:  Moles, Atoms & Electrons |
71%
From NCERT
AIPMT - 2014
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1.0 g of magnesium is burnt with 0.56 g O2 in a closed vessel. Which reactant is left in excess and by how much? (At. wt. Mg = 24; O = 16)

 1 Mg, 0.16 g 2 ${O}_{2}$, 0.16 g 3 Mg, 0.44 g 4 ${O}_{2}$, 0.28 g
Subtopic:  Moles, Atoms & Electrons |
59%
From NCERT
AIPMT - 2014
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The weight of 70 % HNOconcentrated nitric acid solution that should be used to prepare 250 mL of 2.0 M HNO3  is:
1. 90.0 g conc. HNO3
2. 70.0 g conc. HNO3
3. 54.0 g conc. HNO3
4. 45.0 g conc. HNO3
Subtopic:  Concentration Based Problem |
64%
From NCERT
AIPMT - 2013
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6.02 × 1020 molecules of urea are present in 100 mL of its solution. The concentration of the solution is:
1. 0.01 M
2. 0.001 M
3. 0.1 M
4. 0.02 M
Subtopic:  Concentration Based Problem |
77%
From NCERT
AIPMT - 2013
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Mole fraction of solute in a 1.00 molal aqueous solution is:
1.  0.0177
2.  0.0344
3.  1.770
4.  0.1770

Subtopic:  Concentration Based Problem |
82%
From NCERT
AIPMT - 2011
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