Chapter Name - Solutions - 2 | Important Questions for AIIMS, NEET, JEE MAIN & JEE ADV - 2020
---------------------------------------------------------------

#. Answer the following Topics in 6 lines only or 6 points :

T1.Types of Solutions

T2.Expressing Concentration of Solutions

T3.Solubility
1. Solubility of a Solid in a Liquid
2. Solubility of a Gas in a Liquid
3. Vapour Pressure of Liquid Solutions
4. Vapour Pressure of Liquid-Liquid Solutions
5. Raoult’s Law as a special case of Henry’s Law
6. Vapour Pressure of Solutions of Solids in Liquids
7. Ideal and Non - Ideal Solutions
8. Colligative Properties and Determination of Molar Mass
9. Elevation of Boiling Point
10.Depression of Freezing Point
11.Osmosis and Osmotic Pressure
12.Reverse Osmosis and Water Purification

T4.Abnormal Molar Masses

-------------------------------------------------------

Important Questions for AIIMS, NEET, JEE MAIN & JEE ADV - 2020

Q2.1 Define the term solution. How many types of solutions are formed? Write briefly
about each type with an example.

Q2.2 Suppose a solid solution is formed between two substances, one whose particles
are very large and the other whose particles are very small. What kind of solid
solution is this likely to be?

Q2.3 Define the following terms:
(i) Mole fraction (ii) Molality (iii) Molarity (iv) Mass percentage.

Q2.4 Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in
aqueous solution. What should be the molarity of such a sample of the acid if
the density of the solution is 1.504 g mL–1?

Q2.5 A solution of glucose in water is labelled as 10% w/w, what would be the
molality and mole fraction of each component in the solution? If the density of
solution is 1.2 g mL–1, then what shall be the molarity of the solution?

Q2.6 How many mL of 0.1 M HCl are required to react completely with 1 g mixture
of Na2CO3 and NaHCO3 containing equimolar amounts of both?

Q2.7 A solution is obtained by mixing 300 g of 25% solution and 400 g of 40%
solution by mass. Calculate the mass percentage of the resulting solution.

Q2.8 An antifreeze solution is prepared from 222.6 g of ethylene glycol (C2H6O2) and
200 g of water. Calculate the molality of the solution. If the density of the
solution is 1.072 g mL–1, then what shall be the molarity of the solution?

Q2.9 A sample of drinking water was found to be severely contaminated with
chloroform (CHCl3) supposed to be a carcinogen. The level of contamination
was 15 ppm (by mass):
(i) express this in percent by mass
(ii) determine the molality of chloroform in the water sample.

Q2.10 What role does the molecular interaction play in a solution of alcohol and water?

Q2.11 Why do gases always tend to be less soluble in liquids as the temperature
is raised?

Q2.12 State Henry’s law and mention some important applications?

Q2.13 The partial pressure of ethane over a solution containing 6.56 × 10–3 g of
ethane is 1 bar. If the solution contains 5.00 × 10–2 g of ethane, then what
shall be the partial pressure of the gas?

Q2.14 What is meant by positive and negative deviations from Raoult's law and how is
the sign of ΔmixH related to positive and negative deviations from Raoult's law?

Q2.15 An aqueous solution of 2% non-volatile solute exerts a pressure of 1.004 bar
at the normal boiling point of the solvent. What is the molar mass of the solute?

Q2.16 Heptane and octane form an ideal solution. At 373 K, the vapour pressures of
the two liquid components are 105.2 kPa and 46.8 kPa respectively. What will
be the vapour pressure of a mixture of 26.0 g of heptane and 35 g of octane?

Q2.17 The vapour pressure of water is 12.3 kPa at 300 K. Calculate vapour pressure
of 1 molal solution of a non-volatile solute in it.

Q2.18 Calculate the mass of a non-volatile solute (molar mass 40 g mol–1) which
should be dissolved in 114 g octane to reduce its vapour pressure to 80%.

Q2.19 A solution containing 30 g of non-volatile solute exactly in 90 g of water has a
vapour pressure of 2.8 kPa at 298 K. Further, 18 g of water is then added to
the solution and the new vapour pressure becomes 2.9 kPa at 298 K. Calculate:
(i) molar mass of the solute (ii) vapour pressure of water at 298 K.

Q2.20 A 5% solution (by mass) of cane sugar in water has freezing point of 271K.
Calculate the freezing point of 5% glucose in water if freezing point of pure
water is 273.15 K.

Q2.21 Two elements A and B form compounds having formula AB2 and AB4. When
dissolved in 20 g of benzene (C6H6), 1 g of AB2 lowers the freezing point by
2.3 K whereas 1.0 g of AB4 lowers it by 1.3 K. The molar depression constant
for benzene is 5.1 K kg mol–1. Calculate atomic masses of A and B.

Q2.22 At 300 K, 36 g of glucose present in a litre of its solution has an osmotic pressure
of 4.98 bar. If the osmotic pressure of the solution is 1.52 bars at the same
temperature, what would be its concentration?

Q2.23 Suggest the most important type of intermolecular attractive interaction in
the following pairs.
(i) n-hexane and n-octane
(ii) I2 and CCl4
(iii) NaClO4 and water
(iv) methanol and acetone
(v) acetonitrile (CH3CN) and acetone (C3H6O).

Q2.24 Based on solute-solvent interactions, arrange the following in order of increasing
solubility in n-octane and explain. Cyclohexane, KCl, CH3OH, CH3CN.

Q2.25 Amongst the following compounds, identify which are insoluble, partially soluble and highly soluble in water?
(i) phenol (ii) toluene (iii) formic acid
(iv) ethylene glycol (v) chloroform (vi) pentanol.

Q2.26 If the density of some lake water is 1.25g mL–1 and contains 92 g of Na+ions per
kg of water, calculate the molality of Na+ions in the lake.

Q2.27 If the solubility product of CuS is 6 × 10–16, calculate the maximum molarity of
CuS in aqueous solution.

Q2.28 Calculate the mass percentage of aspirin (C9H8O4) in acetonitrile (CH3CN) when
6.5 g of C9H8O4 is dissolved in 450 g of CH3CN.

Q2.29 Nalorphene (C19H21NO3), similar to morphine, is used to combat withdrawal
symptoms in narcotic users. Dose of nalorphene generally given is 1.5 mg.
Calculate the mass of 1.5 – 10–3 m aqueous solution required for the above dose.

Q2.30 Calculate the amount of benzoic acid (C6H5COOH) required for preparing 250
mL of 0.15 M solution in methanol.

Q2.31 The depression in freezing point of water observed for the same amount of
acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order
given above. Explain briefly.

Q2.32 Calculate the depression in the freezing point of water when 10 g of
CH3CH2CHClCOOH is added to 250 g of water. Ka = 1.4 × 10–3, Kf = 1.86K kg mol–1.

Q2.33 19.5 g of CH2FCOOH is dissolved in 500 g of water. The depression in the freezing
point of water observed is 1.00 C. Calculate the van’t Hoff factor and dissociation
constant of fluoroacetic acid.

Q2.34 Vapour pressure of water at 293 K is 17.535 mm Hg. Calculate the vapour
pressure of water at 293 K when 25 g of glucose is dissolved in 450 g of water.

Q2.35 Henry’s law constant for the molality of methane in benzene at 298 K is
4.27 × 105mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.

Q2.36 100 g of liquid A (molar mass 140 g mol–1) was dissolved in 1000 g of liquid B
(molar mass 180 g mol–1). The vapour pressure of pure liquid B was found to be
500 torr. Calculate the vapour pressure of pure liquid A and its vapour pressure
in the solution if the total vapour pressure of the solution is 475 Torr.

Q2.38 Benzene and toluene form ideal solution over the entire range of composition.
The vapour pressure of pure benzene and naphthalene at 300 K are 50.71
mm Hg and 32.06 mm Hg respectively. Calculate the mole fraction of benzene
in vapour phase if 80 g of benzene is mixed with 100 g of naphthalene.

Q2.39 The air is a mixture of a number of gases. The major components are oxygen
and nitrogen with approximate proportion of 20% is to 79% by volume at 298
K. The water is in equilibrium with air at a pressure of 10 atm. At 298 K if the
Henry’s law constants for oxygen and nitrogen at 298 K are 3.30 × 107 mm and 6.51 × 107 mm respectively, calculate the composition of these gases in water.

Q2.40 Determine the amount of CaCl2 (i = 2.47) dissolved in 2.5 litre of water such
that its osmotic pressure is 0.75 atm at 27° C.

Q2.41 Determine the osmotic pressure of a solution prepared by dissolving 25 mg of
K2SO4 in 2 litre of water at 25° C, assuming that it is completely dissociated.

Module I Measurement in Science - HW-01-01

Chapter Name - MEASUREMENT IN SCIENCE AND TECHNOLOGY - 1
---------------------------------------------------------------

#. Answer the following Topics in 6 lines only or 6 points :

T1.WHAT IS A MEASUREMENT?
1. Why do we need to make a measurement?
2. What is a Unit?
3. Characteristics of a Unit

T2.HOW DID OUR ANCESTORS MAKE MEASUREMENTS?
1. Need for a standard unit
2. Indian measurement system
3. (a) Indian measurement system in the ancient period
4. (b) Indian measurement system in the medieval period
5. (c) Indian measurement system during British period
6. Relation between various units of mass used during the British period

T3.THE MODERN MEASUREMENT SYSTEMS

T4.SI UNITS
1. Derived Units
2. SI Prefixes
3. How do we use SI prefixes?
4. Rules for Representing SI Units
-------------------------------------------------------

Important Questions for NIOS - ODE & PE

Q1. Give the common unit to measure our body temperature and write its SI unit
Q2. What are the advantages of SI units?

Module I ORIGIN AND EVOLUTION OF LIFE AND INTRODUCTION TO CLASSIFICATION - HW-01-01

Chapter Name - ORIGIN AND EVOLUTION OF LIFE AND INTRODUCTION TO CLASSIFICATION - 1
---------------------------------------------------------------

#. Answer the following Topics in 6 lines only or 6 points :

T1.ORIGIN OF LIFE
1. Chemosynthetic Theory of Origin of Life
2. Probable stages in the origin of life

T2.ORGANIC EVOLUTION
1. What is Evolution ?
2. According to the Theory of Organic Evolution
3. Evidences of organic evolution
4. Evidences from Morphology
5. Homologous Organs
6. Vestigial Organs
7. Connecting Links
8. Evidences from Embryology
9. Evidences from Paleontology
10.Molecular Evidence of Evolution
11.Mechanism of Evolution
12.Darwin’s Theory of Natural Selection
13.Elemental Forces of Organic Evolution
14.Speciation
15.Sympatric speciation
16.Models of speciation
17.Hardy-Weinberg Equilibrium

T3.CLASSIFICATION
1. Meaning of Classification
2. Taxonomic categories
3. Scientific naming of organisms
4. Prokaryotes and Eukaryotes
5. The Five Kingdoms of Organisms

T4.VIRUSES - AN INTRODUCTION
1. Structure of virus
2. Virus — living or non-living?
3. Infective properties of virus
4. Viruses and diseases
5. Viroids

-------------------------------------------------------

Important Questions for NIOS - ODE & PE

Q1. Explain the most valid theory about origin of life on earth. How did Miller and Urey verify the chemosynthesis theory of evolution?
Q2. Differentiate between Darwinism and Neo-darwinism.
Q3. Explain the synthetic theory of evolution.
Q4. Substantiate the idea of evolution through molecular evidence.
Q5. Classify the following animals : earthworm, roundworm, frog and human-beings.
Q6. Write the scientific names of (i) Mango (ii) Man (iii) Cat (iv) Tiger
Q7 How does a virus increase in number? Show only by explanatory diagrams.
Q8. Give a schematic diagram of the five Kingdom classification.
Q9. State the criteria on which the five kingdom classification is based.

Module I UNITS, DIMENSIONS AND VECTORS - HW-01-01

Chapter Name - UNITS, DIMENSIONS AND VECTORS - 1
---------------------------------------------------------------

#. Answer the following Topics in 6 lines only or 6 points :

T1.  PHYSICAL WORLD AND MEASUREMENTS
1. Physics: Scope and Excitement
2. Nature of Physical Laws
3. Physics, Technology and Society
4. Need of Measurement

T2. UNIT OF MEASUREMENT
1. Measurements in Indian Traditions
2. The SI Units
3. Standards of Mass, Length and Time
4. Significant Figures
5. Importance of significant figures in measurement
6. Importance of significant figures in expressing the result of calculations
7. Significant figures in addition, subtraction, multiplication and division
8. Derived Units
9. Nomenclature and Symbols

T3. DIMENSIONS OF PHYSICAL QUANTITIES
1. Applications of Dimensions (or dimensional equations)

T4. VECTORS AND SCALARS
1. Scalar and Vector Quantities
2. Representation of Vectors
3. Addition of Vectors
4. Parallelogram Law of Vector Addition

T5. MULTIPLICATION OF VECTORS
1. Multiplication of a Vector by a Scalar
2. Scalar Product of Vectors
3. Vector Product of Vectors

T6. RESOLUTION OF VECTORS
T7.  UNIT VECTOR

-------------------------------------------------------

Important Questions for NIOS - ODE & PE

Q1. Discuss the nature of laws of physics.

Q2. How has the application of the laws of physics led to better quality of life?

Q3. What is meant by significant figures in measurement?

Q4. Find the number of significant figures in the following quantity, quoting the relevant laws:
    (i) 426.69 (ii) 4200304.002 (iii) 0.3040 (iv) 4050 m (v) 5000

Q5. The length of an object is 3.486 m, if it is expressed in centimetre (i.e. 348.6cm) will there be any change in number of significant figures in the two cases.

Q6. What are the four applications of the principles of dimensions? On whatprinciple are the above based?

Q7. The mass of the sun is 2 × 1030 kg. The mass of a proton is 2 × 10–27 kg. If thesun was made only of protons, calculate the number of protons in the sun?

Q8. Earlier the wavelength of light was expressed in angstroms. One angstrom equals 10–8 cm. Now the wavelength is expressed in nanometers. How many angstroms make one nanometre?

Q9. A radio station operates at a frequency of 1370 kHz. Express this frequency in GHz.

Q10. How many decimetres are there in a decametre? How many MW are there in one GW?

Module I Origin of Earth and Evolution of the Environment - HW-01-01

Chapter Name - Origin of Earth and Evolution of the Environment - 1
---------------------------------------------------------------

#. Answer the following Topics in 6 lines only or 6 points :

T1. EARTH AS PART OF THE UNIVERSE AND THE SOLAR SYSTEM
T2. ORIGIN OF THE UNIVERSE AND ORIGIN OF THE EARTH
T3. EARTH–THE UNIQUE PLANET WHICH SUSTAINS LIFE

T4. ORIGIN AND EVOLUTION OF LIFE PRIOR TO THE APPEARANCE OF HUMAN BEINGS
1. Biological evolution- from the simple organisms to complex organisms

T5. WHAT IS ENVIRONMENT
A. Abiotic components
B. Biotic components

Module I UNDERSTANDING INDIAN HISTORY - HW-01-01

Chapter Name - UNDERSTANDING INDIAN HISTORY - 1
---------------------------------------------------------------

#. Answer the following Topics in 6 lines only or 6 points :

T1. SOURCES FOR RECONSTRUCTING ANCIENT INDIAN HISTORY

T2. LITERARY SOURCES
1.  RELIGIOUS LITERATURE

T3. SECULAR LITERATURE

T4. NON-LITERARY SOURCES
1.  INSCRIPTIONS
2.  COINS

T5. ARCHAEOLOGY

T6.  ACCOUNT OF FOREIGN TRAVELLERS

T7. CHANGING NOTIONS OF HISTORY

T8. THEMES IN INDIAN HISTORY

Module I Nature of Geography as a discipline - HW-01-01

Chapter Name - Nature of Geography as a discipline - 1
---------------------------------------------------------------

#. Answer the following Topics in 6 lines only or 6 points :

T1. GEOGRAPHY IN DAILY LIFE

T2. DEVELOPMENT OF GEOGRAPHY
(A) Ancient Period
(B) Pre-Modern Period
(C) Modern Period
(D) Recent Period

T3. SCOPE OF GEOGRAPHY

T4. APPROACHES TO STUDY OF GEOGRAPHY
1.  Systematic Approach
2.  Regional Geography

T5. GEOGRAPHY AND SOCIETY

T6. METHODS AND TECHNIQUES OF GEOGRAPHY
(A) Cartography
(B) Quantitative methods in Geography
(C) Regional science method

T7. BRANCHES OF GEOGRAPHY
A. Physical Geography
(i) Astronomical Geography :
(ii) Geomorphology :
(iii) Climatology : 
(iv) Oceanography :
(v) Soil Geography : 
(vi) Bio-geography :
B. Human Geography
(i) Anthropogeography : 
(ii) Cultural geography :
(iii) Economic geeography :
(iv) Political geography : 
(v) Historical geography : 
(vi) Social geography :
(vi) Population geography : 
(viii) Settlement geography :
(C) Regional geography :

T8. GEOGRAPHYAS AN INTERDISCIPLINARY SUBJECT

Module I Some Basic Concepts of Chemistry - HW-01-01

Chapter Name - Atoms, Molecules and Chemical Arithmetic - 1
---------------------------------------------------------------

Q1. Chemistry plays a vital role in many areas of science and technology. What are those areas?

Q2. Who proposed the particulate nature of matter?

Q3. What is law of conservation of mass?

Q4. What is an atom?

Q5. What is a molecule?

Q6. Why is the symbol of sodium Na?

Q7. How is an element different from a compound?

Q8. A sample of nitrogen gas consists of 4.22 × 1023 molecules of nitrogen. How many moles of nitrogen gas are there?

Q9. In a metallic piece of magnesium, 8.46 × 1024 atoms are present. Calculate the amount of magnesium in moles.

Q10. Calculate the number of Cl2 molecules and Cl atoms in 0.25 mol of Cl2 gas. Calculate the molar mass of
     (i) K2SO4 (ii) Ba3(PO4)2. 

Q11.Find out the mass of carbon -12 that would contain 1.0 × 10*19 carbon-12 atoms. Molar mass of O is 16 g mol–1. What is the mass of one atom and
    one molecule of oxygen?

Q12. Calculate the molar mass of hydrogen chloride, HCl.

Q13. Calculate the molar mass of argon atoms, given that the mass of single atom is 6.634 × 10–26 kg.

Q14. Molar mass of O is 16 g mol–1. What is the mass of one atom and one molecule of oxygen?

Q15. Calculate the mass of 1.0 mol of potassium nitrate, KNO3 (atomic masses :K = 39 amu; N = 14 amu, O = 16 amu).

Q16. The formula of sodium phosphate is Na3PO4. What is the mass of 0.146 mol of Na3PO4? (atomic masses : Na = 23.0 amu, P = 31.0 amu; O = 16.0amu).

Q17. In a reaction, 0.5 mol of aluminium is required. Calculate the amount of aluminium required in grams? (atomic mass of Al = 27 amu)

Q18. How many moles of Cu atoms are present in 3.05 g of copper (Relative atomic mass of Cu = 63.5).

Q19. A piece of gold has a mass of 12.6 g. How many moles of gold are present in it? (Relative atomic mass of Au = 197)

Q20. In a combustion reaction of an organic compound, 2.5 mol of CO2 were produced. What volume would it occupy at STP (273K, 1bar) ?

Q21. For the compound Fe3O4, calculate percentage of Fe and O.

Q22. State percent composition for each of the following:(a) C in SrCO3 (b) SO3 in H2SO4

Q23. What are the empirical formulae of substances having the following molecular formulae? H2O2, C6H12, Li2CO3, C2H4O2, S8, H2O, B2H6, O3, S3O9, N2O3

Q24. A compound is composed of atoms of only two elements, carbon and oxygen. If the compound contain 53.1% carbon, what is its empirical formula

Q25. In the manufacture of ammonia by Haber process, nitrogen reacts with hydrogen at high temprature and high pressure in the presence of a catalyst
and gives ammonia.N2(g) + 3H2(g) --> 2NH3(g).How much hydrogen would be needed to produce one metric ton of ammonia?

Q26. When lead sulphide; PbS and lead oxide, PbO, are heated together the products are lead metal and sulphur dioxide, SO2, PbS(s) + 2PbO(s) --> heat --> 3Pb (1) + SO2(g)

Q27. 2.3 g of sodium metal is introduced into a 2L flask filled with chlorine gas at STP (273 K, 1bar). After the reaction is over, find :
(i) What is the limiting reagent in this reaction?
(ii) How many moles of sodium chloride are formed?
(iii) Which substance is left unconsumed at the end of the reaction? Find out its mass in grams.
(iv) What percentage of the substance present in excess is converted into sodium chloride? (Given : Na = 23, Cl = 35.5)

Q28. 2.0 g mixture of MgCO3 and CaCO3 are heated till no further loss of weight takes place. The residue weighs 1.04 g. Find the percentage composition of the mixture. (Mg = 24, Ca = 40, C = 12, O = 16)

Q29. How many atoms are present in a piece of iron that has a mass of 65.0 g/(atomic mass; Fe = 55.9 amu).

Q30. A piece of phosphorus has a mass of 99.2 g. How many moles of phosphorus,P4 are present in it? (atomic mass, P = 31.0 amu)

Q31. Mass of 8.46 × 1024 atoms of fluorine is 266.95 g. Calculate the atomic mass of fluorine.

Q32. A sample of magnesium consists of 1.92 × 1022 Mg atoms. What is the mass of the sample in grams? (atomic mass = 24.3 amu)

Q33. Calculate the molar mass in g mol–1 for each of the following:
(i) Sodium hydroxide, NaOH
(ii) Copper Sulphate CuSO4 .5H2O.
(iii) Sodium Carbonate, Na2CO3 .10H2O

Q34. For 150 gram sample of phosphorus trichloride ( PCl3 ), calculate each of the following:
(i) Mass of one PCl3 molecule.
(ii) The number of moles of PCl3 and Cl in the sample.
(iii)The number of grams of Cl atoms in the sample.
(iv)The number of molecules of PCl3 in the sample.

Q35. Find out the mass of carbon-12, that would contain 1 × 1019 atoms.

Q39. How many atoms are present in 100 g sample of C-12 atom?

Q40. How many moles of CaCO3 would weigh 5 g?

Q41. If you require 1.0 × 1023 molecules of nitrogen for the reaction N2 + 3H2 → 2NH3.
(i) What is the mass (in grams) of N2 required?
(ii) How many moles of NH3 would be formed in the above reaction from 1.0 × 1023 molecules of N2?
(iii) What volume would NH3 gas formed in (ii) occupy at STP?

Q42. Write empirical formulae of the following compounds:CO, Na2SO3, C4H10, H2O2, KC1

Q43. The empirical formula of glucose is CH2O which has a formula mass of 30amu. If the molecular mass of glucose is 180 amu. Determine the molecular formula of glucose

Q44. What is ratio of masses of oxygen that are combined with 1.0 gram of nitrogen in the compound NO and N2O3?

Q46. A compound containing sulphur and oxygen on analysis reveals that it contains 50.1% sulphur and 49.9% oxygen by mass. What is the simplest formula of the compound?

Q47. Hydrocarbons are organic compound composed of hydrogen and carbon.A, 0.1647 g sample of a pure hydrocarbon on burning in a combustion tube produced 0.5694 g of CO2and 0.0845 g of H2O. Determine the percentage of these elements in the hydrocarbon.

Q48. (i) What mass of oxygen is required to react completely with 24 g of CH4 in the following reaction? CH4(g) + 2O2(g) → CO2(g) + 2H2O(1) (ii) How much mass of CH4would react with 96 g of oxygen.

Q49. In the reaction H2+ C12 → 2HC1 How many grams of chlorine, C12 are needed to react completely with 0.245 g of hydrogen, H2, to give hydrogen chloride, HC1? How much HC1 is formed?. 

Q50. 3.65 g of H2 and 26.7 g of O2 are mixed and reacted. How many grams of H2O are formed?. 

Q51. Caustic soda NaOH can be commercially prepared by the reaction of Na2CO3 with slaked line, Ca(OH)2. How many grams of NaOH can be obtained by treating 2.0 kg of Na2CO3 with Ca(OH)2 ?

Q52. A portable hydrogen generator utilizes the reaction CaH2 + H2O → Ca(OH)2 + 2H2 How many grams of H2 can be produced by a 100 g cartridge of CaH2?

Q53. 2.0 g of a mixture of Na2CO3 and NaHCO3 was heated when its weight reduced to 1.876 g. Determine the percentage composition of the mixture.

Q54. Calculate the weight of 60 % sulphuric acid required to decompose 150 g of chalk (calcium carbonate). Given Ca = 40, C = 12, O = 16, S = 32).

Q55. The reaction 2Al + 3MnO → Al2O3+ 3Mn proceeds till the limiting substance is consumed. A mixture of 220 g Al and 400 g MnO was heated to initiate the reaction. Which initial substance remained in excess and by how much ? ( Al = 27, Mn = 55).

Q56. On combustion 2.4 g of a compound of carbon, hydrogen and oxygen gave3.52 g of CO2and 1.44 g of H2O. The molecular mass of the compound was found to be 60.0 amu.(a) What are the masses of carbon, hydrogen and oxygen in 2.4 g of the compound?(b) What are the empirical and molecular formulae of the compound?