MEDIUM

JEE Main

IMPORTANT

Earn 100

${NaClO}_{3}$ is used, even in spacecrafts, to produce $O_{2} .$ The daily consumption of pure $O_{2}$ by a person in $492 L$ at $1$ atm, $300 K .$ How much amount of ${NaClO}_{3},$ in grams, is required to produce $O_{2}$ for the daily consumption of a person at $1$ atm, $300 K$ ?

${NaClO}_{3} (s) + Fe (s) \to O_{2} (g) + NaCl (s) + FeO (s)$
$R = 0 .082 L atm {mol}^{- 1} K^{- 1}$

Give answer to the nearest integer value.

50% studentsanswered this correctly

Important Questions on Some Basic Concepts of Chemistry

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 8th January 2020 Shift 1>Q 25

Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in grams) of the salt required to achieve

10 p p m

of iron in

100 k g

of wheat is ____________. (Up to two decimal place)
Atomic weight:

F e = 55.85; S = 32.00; O = 16.00

EASY

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 8th April 2019 Shift 2>Q 26

The percentage composition of carbon by mole in methane is:

HARD

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 8th April 2019 Shift 2>Q 27

0.27 g

of a long chain fatty acid was dissolved in

100 {c m}^{3}

of hexane.

10 m L

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 c m

. What is the height of the monolayer?
[Density of fatty acid

= 0.9 g c m^{- 3}; π = 3]

HARD

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 8th April 2018>Q 28

The ratio of mass percent of

C and H

of an organic compound

(C_{X} H_{Y} O_{Z})

6 : 1 .

If one molecule of the above compound

(C_{X} H_{Y} O_{Z})

contains half as much oxygen as required to burn one molecule of compound

C_{X} H_{Y}

completely to

{CO}_{2}

and

H_{2} O .

The empirical formula of the compound

C_{X} H_{Y} O_{Z}

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 8th April 2017>Q 29

Excess of

NaOH (aq)

was added to

100 mL

{FeCl}_{3} (aq)

resulting into

2.14 g

Fe {(OH)}_{3}

. The molarity of

{FeCl}_{3} (aq)

is:

(Given the molar mass of

Fe = 56 g

{mol}^{- 1}

and molar mass of

Cl = 35 .5 g {mol}^{- 1}

)

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 7th January 2020 Shift 2>Q 30

Consider the following reactions:

NaCl + K_{2} {Cr}_{2} O_{7} + \underset{(Conc.)}{H_{2} {SO}_{4}} \to (A) +

side products

(A) + N a O H \to (B) +

side products

(B) + \underset{(dilute)}{H_{2} S O_{4}} + H_{2} O_{2} \to (C) +

side products
The sum of the total number of atoms in one molecule each of

(A), (B)

and

(C)

is ________

MEDIUM

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 7th January 2020 Shift 2>Q 31

The flocculation value of

H C l

for arsenic sulphide

s o l

30 m m o l L^{- 1}

. If

H_{2} S O_{4}

is used for the flocculation of arsenic sulphide, the amount, in grams, of

H_{2} S O_{4}

250 m l

required for the above purpose is ________. (Round off to two digits after decimal.)
(molecular mass of

H_{2} {S O}_{4} = 98 g / m o l

EASY

JEE Main

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 1 - Some Basic Concepts of Chemistry>JEE Main - 7th January 2020 Shift 1>Q 32

Amongst the following statements, that which was not proposed by Dalton was :

Important Questions on Some Basic Concepts of Chemistry

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