Practice Chemistry MCQs for OTS Fisheries & Livestock Dept Everyday Science — topic-wise sets with solved answers.
Q1. The most abundant element in the Earth's crust is:
Answer: Oxygen
Explanation: Oxygen is the most abundant element in the Earth's crust by mass, making up about 46% of crustal weight, primarily in the form of oxides and silicates.
Q2. Which of the following is an organic molecule needed by the body in small amounts?
Answer: Vitamin C
Explanation: Vitamins are organic micronutrients required in small amounts for normal metabolic function; Vitamin C (ascorbic acid) is a classic example of such an organic molecule.
Q3. Existence of an element in more than one form in the same physical state is called:
Answer: Allotropy
Explanation: Allotropy is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q4. What is the subatomic particle detected for the first time in 2015 by the European Organization for Nuclear Research?
Answer: Pentaquark
Explanation: In July 2015, CERN's LHCb experiment announced the discovery of pentaquarks - exotic hadrons composed of five quarks - not previously observed as a stable particle state.
Q5. Which of the following elements is not present abundantly in the Earth's crust?
Answer: Radium
Explanation: Radium is an extremely rare radioactive element with a crustal abundance of only about 1 part per trillion, far less abundant than silicon, aluminum, or carbon.
Q6. The second most abundant element found in the Earth's crust is:
Answer: Silicon
Explanation: Silicon is the second most abundant element in Earth's crust at about 28% by mass, after oxygen (~46%), existing mainly as silicon dioxide (SiO₂) and silicate minerals.
Q7. Which part of a plant is particularly in need of phosphorus for its growth?
Answer: Root
Explanation: Phosphorus is essential for root development as it promotes cell division, energy transfer (ATP), and the formation of root tips, making roots particularly dependent on it.
Q8. The exchange of carbon dioxide and oxygen gas between the cell and the atmosphere during photosynthesis takes place by:
Answer: Diffusion
Explanation: Gases (CO₂ and O₂) move between cells and the atmosphere by simple diffusion - moving passively from areas of higher concentration to lower concentration without energy expenditure.
Q9. Four identical kettles with the same amount of water have bases made of different metals of the same thickness. If these are placed on identical flames, water will boil first in the kettle with a base made of:
Answer: Copper
Explanation: Copper has the highest thermal conductivity (about 401 W/m·K) among the options, so it transfers heat from the flame to the water most rapidly, bringing it to boil first.
Q10. In the periodic table, on moving from left to right across a period, the metallic character of an element:
Answer: Decreases
Explanation: Across a period from left to right, nuclear charge increases, pulling electrons closer and reducing atomic radius; this trend increases ionization energy and decreases metallic character.
Q11. A device which converts chemical energy into electrical energy is called a ____.
Answer: Battery
Explanation: A battery converts chemical energy into electrical energy through electrochemical redox reactions between its electrodes and electrolyte.
Q12. A study of the chemical composition of the Earth's crust is called:
Answer: Geology
Explanation: Geology encompasses the study of Earth's composition, structure, and processes, including the chemical makeup of the crust through its sub-discipline geochemistry.
Q13. The rocks formed out of layers of sediment bonded together are known as:
Answer: Sedimentary rocks
Explanation: Sedimentary rocks is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q14. Which chemical element has properties of both a metal and a non-metal?
Answer: Metalloid
Explanation: Metalloids (e.g., silicon, germanium, arsenic) exhibit properties intermediate between metals and non-metals, such as semiconductivity, making them useful in electronics.
Q15. Cu is the symbol of which element of the Periodic Table?
Answer: Copper
Explanation: Copper is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q16. Analytical solutions to quadratic equations were introduced by ______.
Answer: Al-Khwarizmi
Explanation: Al-Khwarizmi, the 9th-century Persian mathematician, systematically presented methods for solving quadratic equations in his foundational work "Al-Kitab al-mukhtasar fi hisab al-jabr wal-muqabala."
Q17. What are the vertical columns in the Periodic Table called?
Answer: Groups
Explanation: In the Periodic Table, vertical columns are called Groups (or families), which contain elements with similar chemical properties and the same number of valence electrons.
Q18. Which of the following elements is not essential for plants?
Answer: Iodine
Explanation: Iodine is an essential micronutrient for humans and animals (needed for thyroid hormones) but is not required for plant growth; plants do not produce iodine-dependent compounds.
Q19. Which element is most abundant in the Universe?
Answer: Hydrogen
Explanation: Hydrogen is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q20. Which of these has the lowest pH?
Answer: Gastric Juice
Explanation: Gastric juice has a pH of approximately 1.5-3.5, making it the most acidic body fluid, far more acidic than saliva (6.5-7.5), bile (~7.8), or pancreatic juice (~8.3).
Loading...