NIOS CHEMISTRY (313) Solved TMA English Medium 2024 to 2025

Note:

(i) All questions are compulsory. The Marks allotted for each question are given beside the questions.

(ii) Write your name, enrollment numbers, AI name and subject on the first page of the answer sheet.

1. Answer any one out of the following questions in about 40 to 60 words.

(a) Classify the elements of group 14, 15 and 16 into metals, non-metals and metalloids. (See Lesson-3)

(b) Write the names of the elements with atomic numbers 105, 109, 112, 115 according to IUPAC nomenclature. (See Lesson-3)

2. Answer any one out of the following questions in about 40 to 60 words.

(a) How do metallic and ionic substances differ in conducting electricity? (See Lesson-3)

(b) The unit cell of a metallic element is face centered cubic and the side of the cube is 540.2 pm. Calculate the density of the metal in gcm–3 if its relative atomic mass is 202.4. (See Lesson-6)

3. Answer any one out of the following questions in about 40 to 60 words.

(a) For the reaction 2NO (g) +O2 (g) → 2NO2 (g) Calculate ΔrG at 700 K when enthalpy and entropy changes (ΔrH and ΔrS) are respectively – 113.0 kJ mol^-1 and –145 JK^-1 mol^-1 (See Lesson-10)

(b) What must be the value of (Ea) if the rate constant for a reaction is doubled when the temperature increases from 300K to 310K? (See Lesson-10)

4. Answer any one out of the following questions in about 100 to 150 words.

(a) Given below is a jumbled sequence of the processes involved in a wastewater treatment plant. Arrange them in their correct sequence.

(i) Sludge is scraped out and skimmer removes floating grease.

(ii) Water is made to settle in a large tank with a slope in the middle.

(iii) Large objects like plastic bags are removed by passing wastewater through bar screens.

(iv) Sand, grit and pebbles are made to settle by decreasing the speed of incoming wastewater.

(v) Wastewater enters a grit and sand removal tank. (See Lesson-32)

(b) Calculate the equilibrium constant for the reaction A(g) + B(g) ⇌ C(g) + D(g) If at equilibrium 1 mol of A, 0.5 mole of B, 3.0 mole of C and 10 mol of D are present in a one litre vessel. (See Lesson-11)

5. Answer any one out of the following questions in about 100 to 150 words.

(a) Describe the underlying principle of each of the following metal refining methods:

(i) Electrolytic refining of metals

(ii) Vapour phase refining of metals (See Lesson-16)

(b) Describe the electrolytic refining method with labeled diagram of copper metal. Write the name of metal which is settled as anode mud. (See Lesson-16)

6. Prepare any one of the project out of two given below in about 500 words.

(a) Complete the table given blow of the contaminant survey. (See Lesson-32)

Types of sewage Point of origin Substance which contaminant Any other remark

Sullage water Kitchen

(b) Chemistry is deeply embedded in our daily experiences. Answer the following questions regarding the presence and impact of chemistry in your everyday life. (See Lesson-32)

(i) How do you perceive the presence of chemistry in your daily routines or activities? Can you identify any specific examples where chemistry plays a significant role? (e.g., food preparation, cleaning products, personal care items, etc.)

(ii) Have you ever considered the chemical composition or reactions behind common household items or products you use? Please provide examples and elaborate on your understanding.

(iii)In what ways does chemistry influence the food you consume or prepare? How do chemical reactions impact cooking or food preservation techniques?

(iv)Can you identify any environmental issues related to chemical usage in everyday life? How do you think these issues could be mitigated or improved?

(v) How does chemistry contribute to advancements in medicine and healthcare? Can you discuss any specific pharmaceutical products or medical procedures that showcase the role of chemistry in improving human health?

(vi)What role does chemistry play in personal hygiene products or cosmetics that you use? Are you aware of any chemical risks associated with these products?