All questions
- E. Colourless components on chromatogram can not be observed by the following : d. Using infrared light 2
- D. A mixture of acetone and benzene can be seperated by the following method : b. Fractional distillation 2
- C. Which technique is widely used in industry to seperate components of mixture and also to purify them ? b. Chromatography 2
- B. Which of the following techniques is used for seperation of glycerol from soap in soap industry ? a. Distillation under reduced pressure 2
- A. Which of the following methods can be used to seperate two compounds with different solubilities in the same solvent? a. Fractional crystallization 2
- Define Analytical chemistry. Why is accurate measurement crucial in science? The accuracy of measurement is of a great concern in analytical chemistry. This is because faulty equipment, poor data processing or human e... 2
- Why does molarity of a solution depend upon temperature ? Molarity is the number of moles of the solute present in 1 litre of the solution. Therefore, molarity depends on the volume of the solution.... 1
- Why there is a need of rounding off figures during calculation ? When performing calculations with measured quantities, the rule is that the accuracy of the final result is limited to the accuracy of the l... 1
- Define : Stoichiometry Calculations based on a balanced chemical equation are known as stoichiometric calculations 2
- Explain the following terms (a) Mole fraction (b) Molarity (c) Molality Mole fraction: It is the ratio of number of moles of a particular component of a solution to the total number of moles of the solution. If a... 1
- What do you mean by SI units ? What is the SI unit of mass ? In 1960, the general conference of weights and measures proposed revised metric system, called International system of Units i.e. SI units,... 1
- What is a limiting reagent ? Explain. Limiting reagent: i. The reactant which gets consumed and limits the amount of product formed is called the limiting reagent. ii. When a che... 1
- Explain the terms percentage composition, empirical formula and molecular formula. Percentage composition: The percentage composition of a compound is the percentage by weight of each element present in the compound. Quanti... 1
- Distinguish between accuracy and precision. Accuracy Precision Accuracy refers to nearness of the measured value to the true value. Precision refers to closeness of multiple readings o... 1
- What do you mean by significant figures? State the rules for deciding significant figures The significant figures in measurement or result are the number of digits known with certainty plus one uncertain digit. Rules for deciding... 1
- Define : Least count The smallest value that can be measured by the measuring instrument is called its least count. 2
- The magnetic flux linked with a coil (in Wb) is given by the equation ϕ = 5t^2 + 3t + 16 The magnitude of induced Given: Magnetic flux (ϕ) = 5t²+ 3t + 16 induced emf = -dφ/dt ε = d(5t²+3t+16/dt =10t+3 Therefore induced e.m.f. , when t=3, |ε₃|=(10×3)+3=33... 1
- A beam of protons with speed 4 × 105 ms–1 enters a uniform magnetic field of 0.3T at an angle of 60º Correct answer is option 3) 4cm Explaination:: Pitch=(Vcosθ)T =(Vcosθ)2π m/eB =(4×10⁵cos60°)2πover0.3×10(1.67×10⁻²⁷over1.69×10¹⁹) = 4cm 1
- In a Young's double slit experiment, light of 500 nm is used to produce an interference pattern. β_(0 )= λ/d = 500 x 10⁻⁹/5 x 10⁻⁵ = 10^(-2 )Radian = 0.57º 2
- Endothermic reaction Endothermic reaction: In endothermic reaction, heat is either absorbed from the surroundings or heat has to supplied from outside. It means... 1
- what is a computer virus? State any four methods by which a virus can infect other programs A incomplete program , which is intentionally made for infecting other programs is known as computer virus. Infection Methods: (a) Append: I... 1
- Computer worm and computer virus Computer worm computer virus It is a complete program it is not a complete program by itself Worm generally consumes system resources virus... 2
- e. Explain the similarity and difference in two events, namely adding NaOH to water and adding CaO to water. Chemical equations involved: 1) Reaction between NaOH and water NaOH(s)+H2O(l)->Na^+_((aq)) + OH^-_((aq)) + triangle (HEAT) 2) Reaction betw... 1
- d. Explain the types of reaction with reference to oxygen and hydrogen. Illustrate with examples. There are main three types of chemical reactions with reference to oxygen and hydrogen: 1.Combination Reaction 2. Decomposition Reaction 3.... 1