SARGODHA BOARD
Chemistry (New Scheme)
(Inter Part-I Class 11th)
Time: 20 minutes
Session (2019)
Objective
Marks: 17
Note: You have choices for each objective type question as A, B, C, and D. The choice which you think is correct, fill that circle in front of that question number with a marker or pen. Cutting or filling two or more circles will result in zero marks for that question.
Q.1: Answer all the following Multiple Choice Questions.
- Molarity of pure water is:
- (a) ½
- (b) 18
- (c) 55.5
- (d) 6
- Which of the following statements is correct about a galvanic cell?
- (a) Anode is negatively charged
- (b) Reduction occurs at the anode
- (c) Cathode is positively charged
- (d) Reduction occurs at the cathode
- With an increase of 10°C, the rate of reaction doubles. This increase in the rate of reaction is due to:
- (a) Increase in the number of collisions between reactant molecules
- (b) Decrease in the activation energy of reactants
- (c) Increase in activation energy of reactants
- (d) Increase in the number of effective collisions
- The mass of one mole of an electron is:
- (a) 2.008 mg
- (b) 0.55 mg
- (c) 0.184 mg
- (d) 1.673 mg
- The largest number of molecules is present in:
- (a) 3.6 g of H₂O
- (b) 4.8 g of C₂H₅OH
- (c) 2.8 g of CO
- (d) 5.4 g of N₂O
- Solvent extraction method is particularly useful for separation when the product to be separated is:
- (a) Non-volatile or thermally unstable
- (b) Volatile or thermally stable
- (c) Non-volatile or thermally stable
- (d) Volatile or thermally unstable
- Equal masses of methane and oxygen are mixed in an empty container at 25°C. The fraction of total pressure exerted by oxygen is:
- (a) ½
- (b) ⅓
- (c) ¼
- (d) ⅕
- Pressure remaining constant, at which temperature will the volume of a gas become twice what it is at 0°C?
- (a) 546°C
- (b) 200°C
- (c) 546 K
- (d) 273 K
- When water freezes at 0°C, its density decreases due to:
- (a) Cubic structure of ice
- (b) Empty spaces present in the structure of ice
- (c) Change in bond lengths
- (d) Change in bond angles
- The molecules of CO₂ in dry ice form:
- (a) Ionic crystals
- (b) Metallic crystals
- (c) Molecular crystals
- (d) Any type of crystals
- The wave number of the light emitted by a certain source is 2×10⁶ m⁻¹. The wavelength of this light will be:
- (a) 500 nm
- (b) 1000 nm
- (c) 200 nm
- (d) 250 nm
- Orbitals having the same energy are called:
- (a) Hybrid orbitals
- (b) Valence orbitals
- (c) Degenerate orbitals
- (d) d-orbitals
- Which of the following molecules has zero dipole moment?
- (a) NH₃
- (b) CHCl₃
- (c) H₂O
- (d) BF₃
- Which of the hydrogen halides has the highest percentage of ionic character?
- (a) HCl
- (b) HF
- (c) HBr
- (d) HI
- The net heat change in a chemical reaction is the same whether it is brought about in one step or several steps. This is known as:
- (a) Henry’s Law
- (b) Joule’s Principle
- (c) Hess’s Law
- (d) Law of Conservation of Energy
- The pH of 10⁻² mol/dm³ of an aqueous solution of H₂SO₄ is:
- (a) 3.0
- (b) 2.7
- (c) 2.0
- (d) 1.5
- An azeotropic mixture of two liquids boils at a lower temperature than either of them when:
- (a) It is saturated
- (b) It shows positive deviation from Raoult’s Law
- (c) It shows negative deviation from Raoult’s Law
- (d) It is metastable
SARGODHA BOARD
Session (2019)
(Inter Part-I Class 11th)
Subjective
Time: 2 hours 40 minutes
Marks: 68
Note: Section I is compulsory. Attempt any 3 questions from Section II.
Section I
Q.2: Write short answers to any Eight parts.
(8 × 2 = 16)
- Differentiate between an atom and a molecule.
- Write the function of Mg(ClO₄)₂ and 50% KOH in combustion analysis.
- Differentiate between empirical and molecular formulas.
- What is the Rf value? Why does it have no units?
- How is a saturated solution prepared?
- Define absolute zero temperature.
- Water vapors do not behave ideally at 273 K. Justify.
- Define one atmospheric pressure. Give its two units.
- Prove that d=PM/RT.
- Define mole fraction and parts per million (ppm).
- Define critical solution temperature and conjugate solutions.
- Write the names of colligative properties of dilute solutions.
Q.3: Write short answers to any Eight parts.
(8 × 2 = 16)
- Why does ice occupy 9% more volume than liquid water?
- How do soaps and detergents perform their cleansing action?
- How can vacuum distillation be used to avoid the decomposition of a sensitive liquid?
- Define molar heat of vaporization.
- Why is the e/m value of cathode rays equal to that of an electron?
- Give the electronic configuration of 24Cr and 20Ca
- Write two properties of positive rays.
- Why is it necessary to decrease the pressure in the discharge tube to obtain cathode rays?
- State the Lowry-Bronsted acid and base theory.
- Define the term activation of a catalyst.
- How does a buffer act?
- Differentiate between homogeneous and heterogeneous catalysis.
Q.4: Write short answers to any Six parts.
(6 × 2 = 12)
- Define a coordinate covalent bond. Give one example.
- How does molecular orbital theory explain the paramagnetic properties of oxygen?
- Ionic compounds are mostly soluble in water but insoluble in non-polar solvents. Give a reason.
- The difference in electronegativity of bonded atoms is an index of the polar nature of a covalent bond. Comment on this statement.
- Define a spontaneous process, giving one example.
- Justify that the heat of formation of a compound is the sum of all the other enthalpies.
- How does the electrochemical series explain the displacement of one metal by another?
- Write down the reaction involved in the working of a NiCad cell.
- Write down the construction of a standard hydrogen electrode (SHE).
Section II
Note: Attempt any three (3) questions.
Q.5:
- (a) Define the yield of a chemical reaction. Also, define two types of yields. How are these two yields related by a mathematical expression?
- (b) Describe covalent solids with reference to:
- (i) Hardness
- (ii) Conductivity
- (iii) Solubility in water
- (iv) Melting points.
Q.6:
- (a) A sample of nitrogen gas is enclosed in a vessel of volume 380 cm³ at 120°C and a pressure of 101325 N/m². This gas is transferred to a 10 dm³ flask and cooled to 27°C. Calculate the pressure in N/m² exerted by the gas at 27°C.
- (b) Define a spectrum. Give the difference between continuous and line spectra.
Q.7:
- (a) Write the main postulates of VSEPR theory.
- (b) How is the heat of combustion measured using a bomb calorimeter?
Q.8:
- (a) Calculate the pH of a buffer solution in which 0.11 molar CH₃COONa and 0.09 molar acetic acid solutions are present. Ka for CH₃COOH is 1.85×10−5
- (b) Describe the half-life method for determining the order of a reaction.
- (c) Explain the effect of temperature on the phenol-water system.
- (d) Describe the electrolysis of molten sodium chloride.
This version has been carefully checked for any errors and rephrased for clarity.