Some Basic Concepts of Chemistry PYQs Set 1 (PDF)

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Mere Teacher · Previous Year Questions NEET Chemistry · Some Basic Concepts of Chemistry · Set 1 (Q1-30)
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1. $How many moles of magnesium phosphate, M g_{3} (P O_{4})_{2} will contain 0.25 mole of oxygen atoms?$ (1) $0.02$ (2) $3.125 \times 1 0^{-2}$ (3) $1.25 \times 1 0^{-2}$ (4) $2.5 \times 1 0^{-2}$ 2. $An element, X has the following isotopic composition: 200 X : 90% 199 X : 8.0% 202 X : 2.0% The weighted average atomic mass of the naturally occurring element X is closest to$ (1) $201 amu$ (2) $202 amu$ (3) $199 amu$ (4) $200 amu$ 3. $Which of the following is the most accurate measurement?$ (1) $9 m$ (2) $9.0m$ (3) $9.00m$ (4) $9.000m$ 4. $The masses of carbondioxide and water (ing) respectively formed during complete combustion of 10 g of glucose at STP are$ (1) $14.66, 18.0$ (2) $14.66, 6.0$ (3) $12.0, 6.0$ (4) $24.0, 12.0$ 5. $10 cm^{3} of 0.1 N monobasic acid requires 15 cm^{3} of sodium hydroxide solution whose normality is$ (1) $0.066 N$ (2) $0.66 N$ (3) $1.5 N$ (4) $0.15 N$ 6. $Temperature of 25^{\circ} C in Fahrenheit and Kelvin scale respectively are$ (1) $77^{\circ} F and 298.15 K$ (2) $17^{\circ} F and 298.15 K$ (3) $45^{\circ} F and 260.15 K$ (4) $47^{\circ} F and 312.15 K$ 7. $Which of the following have same number of significant figures? (A) 0.00253 (B) 1.0003 (C) 15.0 (D)163 Choose the correct answer from the options given below$ (1) $A, B and C only$ (2) $C and D only$ (3) $B and C only$ (4) $A, C and D only$ 8. $100 mL of 0.1 M acetic acid is completely neutralized using a standard solution of NaOH . The volume of ethane obtained at STP after the complete electrolysis of the resulting solution is$ (1) $112 mL$ (2) $56 mL$ (3) $224 mL$ (4) $560 mL$ 9. $Which of the following is not a compound?$ (1) $Common salt$ (2) $Marble$ (3) $Sugar$ (4) $Coal$ 10. $The volume of 1 mole of any pure gas at standard temperature and pressure is always equal to$ (1) $0.022414 m^{3}$ (2) $2.2414 m^{3}$ (3) $22.414 m^{3}$ (4) $0.22414 m^{3}$ 11. $The density of 2 M aqueous solution of NaOH is 1.28 g / cm^{3} . The molality of the solution is [Given that molecular mass of NaOH = 40 g mol^{- 1}]$ (1) $1.20 m$ (2) $1.56 m$ (3) $1.67 m$ (4) $1.32 m$ 12. $The molarity of the solution containing 2.8% (mass / volume) solution of KOH is: (Given atomic mass of K = 39) is:$ (1) $0.1 M$ (2) $0.5 M$ (3) $0.2 M$ (4) $1 M$ 13. $Vapour density of a metal chloride is 83 . If equivalent weight of the metal is 6 , its atomic weight will be\dots\dots\dots\dots.$ (1) $12$ (2) $24$ (3) $18$ (4) $60$ 14. $0.4 g of dihydrogen is made to react with 7.1 g of dichlorine to form hydrogen chloride. The volume of hydrogen chloride formed at 273 K and 1 bar pressure is$ (1) $4.54 L$ (2) $90.8 L$ (3) $45.4 L$ (4) $9.08 L .$ 15. $Magnetite can be reduced with CO to yield iron metal and carbon dioxide. Calculate the mass of magnetite (in kg) needed to obtain 4 kg of iron if the process is 80 % efficient. [Atomic weight of Fe and O are 56 g and 16 g, respectively]$ (1) $15.5$ (2) $5.5$ (3) $17.0$ (4) $6.9$ 16. $1 gram of sodium hydroxide was treated with 25 mL of 0.75 M HCl solution, the mass of sodium hydroxide left unreacted is equal to$ (1) $750 mg$ (2) $250 mg$ (3) $0 mg$ (4) $200 mg$ 17. $What mass of 95 % pure CaCO_{3} will be required to neutralise 50 mL of 0.5 M HCl solution according to the following reaction? CaCO_{3 (s)} + 2 HCl_{(aq)} \to CaCl_{2 (aq)} + CO_{2 (g)} + 2 H_{2} O_{(l)} [Calculate upto second place of decimal point]$ (1) $9.50 g$ (2) $1.25 g$ (3) $1.32 g$ (4) $3.66 g$ 18. $Excess of carbon dioxide is passed through 50 mL of 0.5 M calcium hydroxide solution. After the completion of the reaction, the solution was evaporated to dryness. The solid calcium carbonate was completely neutralised with 0.1 N hydrochloric acid. The volume of hydrochloric acid required is$ (1) $200 ml$ (2) $500 ml$ (3) $400 ml$ (4) $300 ml$ 19. $Amongst the following, identify the species with an atom in +6 oxidation state:$ (1) $[M n O_{4}]^{-}$ (2) $[Cr(CN)_{6}]^{3-}$ (3) $C r_{2} O_{3}$ (4) $C r O_{2} C l_{2}$ 20. $In the final answer of the expression \frac{( 29.2 - 20.2 ) ( 1.79 \times 1 0 ^{5} )}{1.37} . The number of significant figures is$ (1) $1$ (2) $2$ (3) $3$ (4) $4$ 21. $xg of methane was burnt completely in the presence of oxygen. The liberated gases were passed into a solution containing 370 g of Ca (OH)_{2} . The weight of white precipitate obtained was 500 . What is the value of x (in g)? (Given : C = 12; H = 1; Ca = 40; O = 16 u)$ (1) $16$ (2) $80$ (3) $160$ (4) $120$ 22. $The weight percentage of C and H in a hydrocarbon is in the ratio of 4 : 1 . What is its empirical formula?$ (1) $CH$ (2) $CH_{2}$ (3) $CH_{3}$ (4) $CH_{4}$ 23. $On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of CO_{2} and 0.567 g of H_{2} O . The empirical formula mass of compound (X) is g. (Given molar mass in gmol^{- 1} C : 12, H : 1, O : 16)$ (1) $60$ (2) $45$ (3) $30$ (4) $15$ 24. $Which one of the following pairs of compounds illustrates the law of multiple proportions?$ (1) $H_{2} O, Na_{2} O$ (2) $MgO, Na_{2} O$ (3) $Na_{2} O, BaO$ (4) $SnCl_{2}, SnCl_{4}$ 25. $80 mL of a hydrocarbon on mixing with 264 mL of oxygen in a closed U-tube undergoes complete combustion. The residual gases after cooling to 273 K occupy 224 mL. When the system is treated with KOH solution, the volume decreases to 64 mL. The formula of the hydrocarbon is:$ (1) $C_{2} H_{2}$ (2) $C_{2} H_{4}$ (3) $C_{2} H_{6}$ (4) $C_{4} H_{10}$ 26. $In the balanced equation of the following reaction, the ratio of \frac{a}{b} is a a CaCO_{3} + b H_{3} PO_{4} ⟶ p Ca_{3} (PO_{4})_{2} + q CO_{2} + r H_{2} O$ (1) $\frac{2}{3}$ (2) $\frac{3}{2}$ (3) $\frac{1}{2}$ (4) $\frac{7}{5}$ 27. $The volume of 0.02 M acidified permanganate solution required for complete reaction of 60 mL, of 0.01 MI^{-} ion solution to from I_{2} in mL is$ (1) $60$ (2) $20$ (3) $40$ (4) $6$ 28. $A sample of N a C l O_{3} is converted by heat to NaCl with a loss of 0.16 g of oxygen. The residue is dissolved in water and precipitated as AgCl. The mass of AgCl (in g) obtained will be: (Given: Molar mass of AgCl = 143.5 g m o l^{-1})$ (1) $0.35$ (2) $0.54$ (3) $0.41$ (4) $0.48$ 29. $Which of the following options is not correct?$ (1) $2.300 + 0.02017 + 0.02015 = 2.340$ (2) $126,000 has 3 significant figures.$ (3) $15.15 μ s = 1.515 \times 1 0^{- 5} s$ (4) $0.0048 = 48 \times 1 0^{- 3}$ 30. $10 mL of 2 M NaOH solution is added to 20 mL of 1 M HCl solution kept in a beaker. Now, 10 mL of this mixture is poured into a volumetric flask of 100 mL containing 2 moles of HCl and made the volume upto the mark with distilled water. The solution in this flask is:$ (1) $0.2 M NaCl solution$ (2) $20 M HCl solution$ (3) $Neutral solution$ (4) $10 M HCl solution$