Some basic concepts OF Chemistry
189 Questions
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JEE (Advanced) 2021
Q26
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8. Question Stem
Numerical
Reaction of x g of Sn with HCl quantitatively produced a salt. Entire amount of the salt reacted with y g of nitrobenzene in the presence of required amount of HCl to produce 1.29 g of an organic salt (quantitatively). (Use Molar masses (in g mol $^{-1}$ ) of H, C, N, O, Cl and Sn as 1, 12, 14, 16, 35 and 119 respectively).
The value of y is
[JEE (Advanced) 2021]
Correct Answer: 1.23
Explanation:
$(72+8+35)+14$ = 129 gm (molecular weight of organic salt)
So to get 1.29 gm organic salt.
We have to form 0.01 mole salt.
So 0.01 mole nitrobenzene is required.
So to get 1.29 gm organic salt.
We have to form 0.01 mole salt.
So 0.01 mole nitrobenzene is required.
JEE (Main) m. 2020. April 2024
Q27
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6. Latest Trend
MCQ
Amongst the following statements, that which was not proposed by Dalton was
A.
All the atoms of a given element have identical properties including identical mass. Atoms of different elements differ in mass
B.
Chemical reactions involve reorganisation of atoms. These are neither created nor destroyed in a chemical reaction
C.
When gases combine or reproduced in a chemical reaction they do so in a simple ratio by volume provided all gases are at the same T and P
D.
Matter consists of indivisible atoms
JEE (Main) Sep. 2020
Q28
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6. Latest Trend
MCQ
The strengths of 5.6 volume hydrogen peroxide (of density $1\mathrm{g} / \mathrm{mL}$ ) in terms of mass percentage and molarity (M) respectively, are (Take molar mass of hydrogen peroxide as $34\mathrm{g} / \mathrm{mol}$ )
A.
1.7 and 0.5
B.
0.85 and 0.5
C.
1.7 and 0.25
D.
0.85 and 0.25
JEE (Main) Sep. 2020
Q29
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6. Latest Trend
MCQ
The average molar mass of chlorine is $35.5 \, g mol^{-1}$ . The ratio of ${}^{35}Cl$ to ${}^{37}Cl$ in naturally occurring chlorine is close to
A.
3:1
B.
4:1
C.
2:1
D.
1:1
JEE (Advanced) 2020
Q30
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7. JEE Section
Numerical
Aluminium reacts with sulphuric acid to form aluminium sulphate and hydrogen. What is the volume of hydrogen gas in litres (L) produced at 300 K and 1.0 atm paressure, when 5.4 g of aluminium and 50.0 mL of 5.0 M sulphuric acid are combined for the reaction
Correct Answer: 6
Explanation:
$2Al + 3H_{2}SO_{4} \rightarrow Al_{2}(SO_{4})_{3} + 3H_{2}$ Moles of Al takes = $\frac{5.4}{27} = 0.2$ Moles of $H_{2}SO_{4}$ taken = $\frac{50 \times 5.0}{1000} = 0.25$ As $\frac{0.2}{2} > \frac{0.25}{3}$ , $H_{2}SO_{4}$ is limiting reagent
Now, moles of $H_{2}$ formed = $\frac{3}{3} \times 0.25 = 0.25$ ā“ Volume of $H_{2}$ gas formed = $\frac{nRT}{P}$ $= \frac{0.25 \times 0.082 \times 300}{1} = 6.15 \ L.$
Now, moles of $H_{2}$ formed = $\frac{3}{3} \times 0.25 = 0.25$ ā“ Volume of $H_{2}$ gas formed = $\frac{nRT}{P}$ $= \frac{0.25 \times 0.082 \times 300}{1} = 6.15 \ L.$
JEE (Main) Jan. 2019
Q31
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6. Latest Trend
MCQ
A solution of sodium sulfate contains 92g of $Na^{+}$ ions per kilogram of water. The molality of $Na^{+}$ ions in that solution in mol $kg^{-1}$ is
A.
16
B.
8
C.
4
D.
12
JEE (Main) Jan. 2019
Q32
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6. Latest Trend
MCQ
For the following reaction, the mass of water produced from 445 g of $C_{57}H_{110}O_{6}$ is $2C_{57}H_{110}O_{6}(s)+163O_{2}(g)\rightarrow114CO_{2}(g)+110H_{2}O(l)$
A.
495 g
B.
490 g
C.
890 g
D.
445 g
JEE (Main) Jan. 2019
Q33
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6. Latest Trend
MCQ
The amount of sugar $(C_{12}H_{22}O_{11})$ required to prepare 2L of its 0.1M aqueous solution is
A.
68.4 g
B.
17.1 g
C.
34.2 g
D.
136.8 g
JEE (Main) Jan. 2019
Q34
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6. Latest Trend
MCQ
In the reaction of oxalate with permaganate in acidic medium, the number of electrons involved in producing one molecule of $CO_{2}$ is
A.
10
B.
2
C.
1
D.
5
JEE (Main) Jan. 2019
Q35
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6. Latest Trend
MCQ
A 10 mg effervescent tablet containing sodium bicarbonate and oxalic acid releases 0.25ml of $CO_{2}$ at T = 298.15K and p = 1 bar. If molar volume of $CO_{2}$ is 25.0 L under such condition, what is the percentage of sodium bicarbonate in each tablet [Molar mass of $NaHCO_{3} = 84gmol^{-1}$ ]
A.
16.8
B.
8.4
C.
0.84
D.
33.6
JEE (Main) Jan. 2019
Q36
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6. Latest Trend
MCQ
8g of NaOH is dissolved in 18g of $H_{2}O$ . Mole fraction of NaOH in solution and molality (in mol kg $^{-1}$ ) of the solutions respectively are
A.
0.167, 11.11
B.
0.2, 22.20
C.
0.2, 11.11
D.
0.167, 22.20
JEE (Main) April 2019
Q37
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6. Latest Trend
MCQ
0.27 g of a long chain fatty acid was dissolved in 100 $cm^3$ of hexane. 10 $mL$ of this solution was added dropwise to the surface of water in a round watch glass. Hexane evaporates and a monolayer is formed. The distance from edge to centre of the watch glass is 10 cm. What is the height of the monolayer?
[Density of fatty acid = 0.9 $g,cm^{-3}$, $\pi = 3$]
[JEE (Main) April 2019]
A.
$10^{-8}$ m
B.
$10^{-6}$ m
C.
$10^{-4}$ m
D.
$10^{-2}$ m
JEE (Main) April 2019
Q38
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6. Latest Trend
MCQ
For a reaction, $N_{2}(g) + 3H_{2}(g)\rightarrow 2NH_{3}(g);$ identify dihydrogen $(H_{2})$ as a limiting reagent in the following reaction mixtures
A.
$14g$ of $N_{2} + 4g$ of $H_{2}$
B.
$28g$ of $N_{2} + 6g$ of $H_{2}$
C.
$56g$ of $N_{2} + 10g$ of $H_{2}$
D.
$35g$ of $N_{2} + 8g$ of $H_{2}$
JEE (Main) April 2019
Q39
Errorless
6. Latest Trend
MCQ
The minimum amount $O_{2}(g)$ consumed per gram of reactant is for the reaction
(Given atomic mass: Fe = 56, O = 16, Mg = 24, P = 31, C = 12, H = 1)
A.
$C_{3}H_{8}(g) + 5O_{2}(g) \rightarrow 3CO_{2}(g) + 4H_{2}O(l)$
B.
$P_{4}(s) + 5O_{2}(g) \rightarrow P_{4}O_{10}(s)$
C.
$4Fe(s) + 3O_{2}(g) \rightarrow 2FeO_{3}(s)$
D.
$2Mg(s) + O_{2}(g) \rightarrow 2MgO(s)$
JEE (Main) April 2019
Q40
Errorless
6. Latest Trend
MCQ
5 moles of $AB_2$ weigh $125 \times 10^{-3} \, \text{kg}$ and 10 moles of $A_2B_2$ weight $300 \times 10^{-3} \, \text{kg}$ . The molar mass of $A(M_A)$ and molar mass of $B(M_B)$ in $\text{kg mol}^{-1}$ are
A.
$M_A = 50 \times 10^{-3}$ and $M_B = 25 \times 10^{-3}$
B.
$M_A = 25 \times 10^{-3}$ and $M_B = 50 \times 10^{-3}$
C.
$M_A = 5 \times 10^{-3}$ and $M_B = 10 \times 10^{-3}$
D.
$M_A = 10 \times 10^{-3}$ and $M_B = 5 \times 10^{-3}$
JEE (Main) April 2019, Jan. 2024
Q41
Errorless
6. Latest Trend
MCQ
Which of the following reactions are disproportionation reactions
A. $Cu^{+} \rightarrow Cu^{2+} + Cu$ B. $3MnO_{4}^{2-} + 4H^{+} \rightarrow 2MnO_{4}^{-} + MnO_{2} + 2H_{2}O$ C. $2KMnO_{4} \rightarrow K_{2}MnO_{4} + MnO_{2} + O_{2}$ D. $2MnO_{4}^{-} + 3Mn^{2+} + 2H_{2}O \rightarrow 5MnO_{2} + 4H^{+}$
Choose the correct answer from the options given below
A.
A, B, C
B.
B, C, D
C.
A, B
D.
A, D
NEET 2017
Q42
Errorless
4. Chemical Stoichiometry
MCQ
The correct order of the stoichiometries of AgCl formed when $AgNO_{3}$ in excess is treated with the complexes $CoCl_{3}.6NH_{3}$ , $CoCl_{3}.5NH_{3}$ , $CoCl_{3}.4NH_{3}$ respectively is
A.
3AgCl, 1AgCl, 2AgCl
B.
3AgCl, 2AgCl, 1AgCl
C.
2AgCl, 3AgCl, 1AgCl
D.
1AgCl, 3AgCl, 2AgCl
JEE (Main) 2017
Q43
Errorless
5. Critical Thinking
MCQ
1 gram of a carbonate ( $M_{2}CO_{3}$ ) on treatment with excess HCl produces 0.01186 mole of $CO_{2}$ . The molar mass of $M_{2}CO_{3}$ in g mol $^{-1}$ is
A.
84.3
B.
118.6
C.
11.86
JEE (Main) 2017
Q44
Errorless
5. Critical Thinking
MCQ
The most abundant elements by mass in the body of a healthy human adult are: Oxygen (61.4%); Carbon (22.9%), Hydrogen (10.0%); and Nitrogen (2.6%). The weight which a 75 kg person would gain if all ${}^{1}$ H atoms are replaced by ${}^{2}$ H atoms is
A.
37.5 kg
B.
7.5 kg
C.
10 kg
D.
15 kg
WB JEE 2016
Q45
Errorless
4. Chemical Stoichiometry
MCQ
If $CO_{2}$ gas is passed through 500 ml of 0.5(M) $Ca(OH)_{2}$ , the amount of $CaCO_{3}$ produced is
A.
10 g
B.
20 g
C.
50 g
D.
25 g
JEE (Advanced) 2016
Q46
Errorless
7. JEE Section
Numerical
In neutral or faintly alkaline solution, 8 moles of permanganate anion quantitatively oxidize thiosulphate anions to produce X moles of a sulphur containing product. The magnitude of X is
Correct Answer: 6
Explanation:
$8 M n O _ {4} ^ {-} + 3 S _ {2} O _ {3} ^ {2 -} + H _ {2} O \xrightarrow {\text { Faintly alkaline }} 8 M n O _ {2}$
$+ 6 S O _ {4} ^ {2 -} + 2 O H ^ {-}$
$M n O _ {4} ^ {-}$
$S O _ {4} ^ {2 -}$
$+ 6 S O _ {4} ^ {2 -} + 2 O H ^ {-}$
$M n O _ {4} ^ {-}$
$S O _ {4} ^ {2 -}$
AIPMT Cancelled 2015; NEET 2018
Q47
Errorless
3. The Mole Concept
MCQ
In which case is the number of molecules of water maximum
A.
18 mL of water
B.
0.18 g of water
C.
0.00224 L of water vapours at 1 atm and 273 K
D.
$10^{-3}$ mol of water
AIPMT (Cancelled) 2015
Q48
Errorless
3. The Mole Concept
MCQ
If Avogadro number $N_{A}$ , is changed from $6.022 \times 10^{23} mol^{-1}$ to $6.022 \times 10^{20} mol^{-1}$ this would change
A.
The definition of mass in units of grams
B.
The mass of one mole of carbon
C.
The ratio of chemical species to each other in a balanced equation
D.
The ratio of elements to each other in a compound
JEE (Advanced) 2015
Q49
Errorless
7. JEE Section
Numerical
In dilute aqueous $H_{2}SO_{4}$ , the complex diaquodioxalatoferrate (II) is oxidized by $MnO_{4}^{-}$ . For this reaction, the ratio of the rate of change of $[H^{+}]$ to the rate of change of $[MnO_{4}^{-}]$ is
Correct Answer: 8
Explanation:
$8H^{+} + MnO_{4}^{-} + [Fe(H_{2}O)_{2}(OX)_{2}]^{2-}\longrightarrow$ $Mn^{2+} + Fe^{3+} + 4CO_{2} + 6H_{2}O$ $\frac{\text{rate of change of }[H^{+}]}{\text{rate of change of }[MnO_{4}^{-}]} = 8$
CBSE PMT 2014
Q50
Errorless
3. The Mole Concept
MCQ
When 22.4 litres of $H_{2}(g)$ is mixed with 11.2 litres of $Cl_{2}(g)$ , each at STP, the moles of $HCl(g)$ formed is equal to
A.
0.5 mol of $HCl(g)$
B.
1.5 mol of $HCl(g)$
C.
1 mol of $HCl(g)$
D.
2 mol of $HCl(g)$