Basic Concepts in Chemistry
2C57H110O6(s) + 163 O2(g) → 114CO2(g) + 110H2O(l)
(Atomic weights in g mol–1: O = 16, S = 32, Pb = 207)
MnCl2 + K2S2O8 + H2O → KMnO4 + H2SO4 + HCl (equation not balanced).
Few drops of concentrated HCl were added to this solution and gently warmed. Further, oxalic acid (225 mg) was added in portions till the colour of the permanganate ion disappeared. The quantity of MnCl2 (in mg) present in the initial solution is ____.
(Atomic weights in g mol−1: Mn = 55, Cl = 35.5)
(Hint: Allene is 1,2-propadiene i.e. H2C = C = CH2)
|Column I||Column II|
|(Molecules)||(Number of lone pairs on central atom)|
Na+, Mg2+, Al3+
Which of the following statements is correct for a liquid and its vapour at boiling point?
How can the paths given in List I be correctly matched with the magnitudes of the work done in List II?
|List I||List II|
|P.||C → A||1.||24P0V0 [3ln2 + ln3]|
|Q.||C → D||2.||23 P0V0|
|R.||B → C||3.||17.2 P0V0|
Given: log 2 = 0.3010, log 3 = 0.4771
Given: log 2 = 0.3010, log 7 = 0.8451, log 3 = 0.4771
N2O4 (g) 2 NO2 (g)
At 55 °C and 1 atm, the percentage decomposition of N2O4 is 40. At what pressure (p) the equilibrium mixture will have the ratio N2O4 : NO2 as 1 : 8?
In a second experiment (Experiment 2), 100 mL of 2.0 M acetic acid solution (Ka = 2.0 × 10−5) was mixed with 100 mL of 2.0 M NaOH solution (under identical conditions as in Experiment 1) where a temperature rise of 11.2 °C was measured. (Consider heat capacity of all solutions as 4.2 J g−1 K−1 and density of all solutions as 1.0 g mL−1)
Magnitude of enthalpy of dissociation (in kJ mol−1) of acetic acid obtained from the Experiment 2 is
(Given: ΔfG° values of CH4(g) = − 693.5 kJ mol−1 , CO2 (g) = −421.2 kJ mol−1 and H2O(l) = −227.4 kJ mol−1, antilog (0.98) = 9.65)
(At. Wt.: Mg = 24)
(Ag = 107.8, N = 14, O = 16, Na = 23 and Cl = 35.5)
(At. wt. Mg = 24; O = 16)
6.02 × 1020 molecules of urea are present in 100 mL of its solution. The concentration of solution is :
A compound with molecular mass 180 is acylated with CH3COCl to get a compound with molecular mass 390. The number of amino groups present per molecule of the former compound is :
A gaseous hydrocarbon gives upon combustion 0.72 g. of water and 3.08 g. of CO2. The empirical formula of the hydrocarbon is :
How many litres of water must be added to 1 litre of an aqueous solution of HCl with a pH of 1 to create an aqueous solution with pH of 2 ?
Experimentally it was found that a metal oxide has formula M0.98O. Metal M, is present as M2+ and M3+ in its oxide. Fraction of the metal which exists as M3+ would be :
How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2.0M HNO3? The concentrated acid is 70% HNO3.
25 mL of household bleach solution was mixed with 30 mL of 0.50 M KI and 10 mL of 4N acetic acid. In the titration of the liberated iodine, 48 mL of was used to reach the end point. The morality of the household bleach solution is
Assertion : Equal moles of different substances contain same number of constituent particles.
Reason : Equal weights of different substances contain the same number of constituent particles.
Dissolving 120g of urea (mol.wt 60) in 1000g of water gave a solution of density 1.15g/mL. The molarity of the solution is
480 mL of 1.5 M first solution +520 mL of 1.2 M second solution.
What is the molarity of the final mixture?
The volume (in mL) of 0.1M AgNO3 required for complete precipitation of chloride ions present in 30mL of 0.01 M solution of as silver chloride is close to
Reason : The molarity of a solution depends upon the density of the solution whereas molality does not.
Reason H2C2O4.2H2O is a dihydrate organic acid.
(A) 6.023 × 1023
(B) 1/9.108 × 1031
(C) 6.023/9.108 × 1054
(D) 1/(9.108 × 6.023) × 108
Considering the absence of any interfering species, the solution required 50 mL of 0.02 M K2Cr2O7 solution for titration.
What is the percentage of CuFeS2 in the mineral?
[Given, Cu = 63.5, Fe = 55.8, S = 32.0, 0 = 16.0]
A 20 L mixture of ethene and ethyne reacts with 58 L of oxygen gas. In the process, both the gases undergo complete combustion. The ratio of the percentage of ethene to that of ethyne in the given mixture is X : 1. What is X?
Equal masses of each SO2, CH4 and O2 are mixed at 298 K in an empty container. The total pressure is recorded 2.1 atm. The partial pressure of CH4 in the mixture is
How much Cl2 is needed to prepare 122.5g NaClO4 by above sequence?
How much Cl2 is needed to prepare 106.5 g of NaClO3 by the above sequence?
|Assertion||:||In acidic medium, equivalent mass of K2Cr2O7 is 49.|
A solid mixture (5.0 g) consisting of lead nitrate and sodium nitrate was heated below 600oC until the weight of the residue was constant. If the loss in weight is 28.0 per cent, the amount of lead nitrate in the mixture is;
A gaseous mixture contains oxygen and nitrogen in the ratio of 1:4 by mass. Therefore, the ratio of their number of molecules is;
Assertion: Unit of specific gravity is gravity is g/cc.
Reason: Specific gravity is same as density of a liquid in normal conditions.
Choose the correct option.
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
(b) If both Assertion and Reason are true but the reason is not the correct explanation of the Assertion
(c) If Assertion is true but Reason is false
(d) If both Assertion and Reason are false
Assertion : Equivalent mass depends upon the nature of chemical reaction in which substance takes part.
Reason : The substance reacts in the mass ratio of their equivalent mass ratio.
Which one of the following step￼s is rate determining step?
A sample of hard water was collected from a tube well and was found to contain 50 milligrams of calcium ions per litre. The number of milliequivalents of sodium carbonate required to soften 800 mL of the hard water sample is
(Reaction with unsymmetrical alkene)
|P. H⊕/H2O||1. No rearrangement of carbocation|
|Q. Hydroboration oxidation||2. Formation of carbon free radical|
|R. HBr/Peroxide||3. Rearrangement of carbocation|
If one hydrogen atom is replaced with a chlorine atom?
MgCl2, CH2Cl2, Na2SO4, Mg(CH3COO)2
What is the number of moles of the product formed when five moles of silica are treated with six moles of boron?
|List I||List II|
|List I||List II|
|P.||Collodion solution||1.||Congo red sol|
|Q.||Negative sol||2.||Methylene blue sol|
|R.||Positively charged sol||3.||4% solution of niro cellulose in alcohol and ether|
Molybdenum act as a __________ and iron is used as a __________.
Fill in the blanks with proper options
Assuming ideal behaviour of all the gases, calculate the density of equilibrium mixture at 500 K and 1.0 atm.
(Atomic mass of P = 31.0 and Cl = 35.5)
I. Occurrence of chemical reaction reaction on the catalyst's surface through formation of an intermediate
II. Diffusion of reaction products away from the catalyst's surface
III. Adsorption of reactant molecules on the surface of the catalyst
IV. Diffusion of reactants to the surface of the catalyst
Fill in the blanks with correct option.
A sample of oleum labelled as 102.85% and weighing 8 g is diluted with water to make a solution. This solution is then titrated against N/10 NaOH solution and the equivalence point is obtained at 1.672 L of N/10 NaOH solution. What is the percentage of free oleum in the solution?
Consider reaction R→P.
[R] at different time interval is given below.
[R]/ mol L-1
50 × 10–2
30 × 10–2
10 × 10–2
5 × 10–2
The ratio of average rate of reaction between the time interval 0 − 20, 20 − 40 and 40 − 60 is
Use the following information to answer the next question.
S reacts with P in presence of the catalyst X to produce R.
The energy diagram for the reaction is given.
Which of the following diagrams represents the energy diagram for the given reaction in the absence of the catalyst?
Consider the statements given below.
(i) They are crystalline solids.
(ii) They are generally very soft.
(iii) Their common examples are CH4, NaBH4, etc.
(iv) They are binary compounds of hydrogen and metallic elements.
Information in which of the above given statements are correct for saline hydrides?
metal (NA = 6.02 × 1023 mol–1)
Use the following information to answer the question:
Magnetite, Fe3O4, is weakly attracted by magnetic field. On heating, it becomes paramagnetic. In presence of magnetite field, magnetic moments of domains are aligned in parallel and anti-parallel direction in unequal numbers.
What kind of magnetism is possessed by magnetite?
Use the following information to answer the next question.
The Lewis structure of ozone (O3) molecule is shown in the given figure.
The three oxygen atoms are marked as I, II, and III.
The respective formal charges on oxygen atoms I, II, and III are
Molar conductivity against concentration curve is shown below.
Which of the following statements is incorrect regarding the graph?
ScN, TiC, MgO, NaF
A certain weed of mass 3.5 × 10–4 g absorbs 5.6 × 10–5 moles of CO2 per hour by photosynthesis. The reaction involved is given below.
How much time will the weed take to increase its mass by 50%, provided all the carbon of CO2 is converted into starch?
Which of the following gives statements is correct w.r.t the data provided?
π, 0·0025, 8000, 6·022 × 1023, 12 eggs, 1kg
A sample of iron (III) oxide weighing 2 g was labelled as 64% pure. It was dissolved in acid and the oxide was reduced with the help of zinc dust, and heated. The solution obtained was cooled and its volume was increased to 200 ml. 50 ml of the solution needed 34 ml of 0.03 M of oxidising agent for oxidation. What is the number of electrons taken up by the oxidising agent?
Calculate the threshold frequency () for the metal (h = 6.6 × 10–34 J-s)
Mg + S → MgS , when 3.00 g of Mg reacts with 3.00 g of sulphur.
When calcium oxide (CaO) reacts with carbon in an electric furnace, crude calcium carbide (CaC2) of 85% purity is formed. Calculate the amount of calcium oxide required to produce 1000 kg pure CaC2.
The sulphate of a metal X contains 25% of X. This sulphate is isomorphous with CuSO4.5H2O. The atomic mass of X is
2 L of mixture X + excess AgNO3 → Y
2 L of mixture X + excess BaCl2 → Z
The number of moles of y and Z are
What is the molarity of the solutions when (i) 0.50 L of 0.01 M HNO3 solution and (ii) 0.75 L of 0.050 M HNO3 solution are put in a single vessel?
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion and reason are true but the reason is not the correct explanation of the assertion.
(c) If assertion is true statement but reason is false.
(d) If both assertion and reason are false.
Assertion : A solution which does not obey raoult's law has .
Reason : A solution of carbon disulphide and acetone has total vapour pressure greater than the vapour pressure of individual components.
A beaker contains 200 mL of 0.2 M NaOH solution. Which of the following processes should be carried out to make it 0.5 M NaOH solution?
(At. wt. of Cl= 35.45 and Cs= 132.91)
Calculate the ratio of density of NaCl and KCl?
n1 → lower orbit
n2 → higher orbit
|Column I||Column II|
|c||NaOH + HCl → NaCl + H2O||r||Process of formation|
|d||s||used in fuel cell|
Which of the following option is correct match:
A + B → C + D
A + C → E
If 2 moles of A is taken and percentage yield of the reaction is 80%, find mass of E produced. [mol. mass E = 20]
[Planck's constant, h = 6.625 × 10–34 J-s 1 eV = 1.6 × 10–19 J]
Which is limiting reactant of the reaction that takes place in the solution?
What will be molality of Pb2+ in the solution after completion of reaction?
Speed of light (c) = 3 × 1017 nm s–1
Frequency of light (v) = 6 × 1015 s–1
Value of wavelength (λ) in nanometer is approximately
Particles of matter are in continuous motion. Which of the following examples supports this statement?