Tags Class 12th

Class 12th

Get insights from 11.9k questions on Class 12th, answered by students, alumni, and experts. You may also ask and answer any question you like about Class 12th

Follow Ask Question

11.9k

Questions

Discussions

Active Users

Followers

New answer posted

11 months ago

Class 12th Chemistry Chemical Kinetics

The reaction rate for the reaction

${[P t C l_{4}]}^{2 -} + H_{2} O \overset{}{?} {[P t (H_{2} O) C l_{3}]}^{-} + C l^{-}$

was measured as a function of concentrations of different species. It was observed that

$\frac{- d {[[P t C l_{4}]]}^{2 -}}{d t} = 4.8 * 1 0^{- 5} [{[P t C l_{4}]}^{2 -}] - 2.4 * 1 0^{- 3} [{[P t (H_{2} O) C l_{3}]}^{-}] [C l^{-}]$

where square bracket are used to denote molar concentrations. The equilibrium constant K_C= ________. (Nearest integer)

0 Follower 7 Views

alok kumar singh

Contributor-Level 10

${[P t C l_{4}]}^{2 -} + H_{2} O ? {[P t (H_{2} O) C l_{3}]}^{-} + C l^{-}$

At equilibrium $\frac{d x}{d t} = 0,$ hence

$0 = \frac{- d [{[P t C l_{4}]}^{2 -}]}{d t} = 4.8 * 1 0^{- 5} [{[P t C l_{4}]}^{2 -}] - 2.4 * 1 0^{- 3} [{[P t (H_{2} O) C l_{3}]}^{-}] [C l^{-}]$

$K_{c} = \frac{K_{f}}{K_{b}} = \frac{4.8 * 1 0^{- 5}}{2.4 * 1 0^{- 3}}$

= 2 * 10^-2

= 0.02

0 0

New answer posted

11 months ago

Class 12th The d and f Block Elements

Which one of the following when dissolved in water gives coloured solution in nitrogen atmosphere?

0 Follower 3 Views

Vishal Baghel

Contributor-Level 10

Cu₂Cl₂ + Water -> Insoluble

AgCl + Water -> Insoluble

ZnCl₂ + Water -> Colouless solution

CuCl₂ + Water -> Coloured solution due to 3d⁹ electronic configuration.

0 0

New answer posted

11 months ago

Class 12th Chemistry Electrochemistry

Given below are two statements:

Statement I : The limiting molar conductivity of KCl (strong electrolyte) is higher compared to that of CH₃COOH (weak electrolyte)

Statement II : Molar conductivity decreases with decrease in concentration of electrolyte.

In the light of the above statements, choose the most appropriate answer from the options given below:

0 Follower 10 Views

Vishal Baghel

Contributor-Level 10

Molar conductivity measured at infinite dilution is called limiting molar conductivity. Hence at infinite dilution stage, both strong electrolyte (KCl) and weak electrolyte (CH₃COOH) have identical value of conductivity. Therefore statement – I is false.

Statement – II is also false because molar conductivity increases by the decreasing the concentration of electrolyte.

0 0

New answer posted

11 months ago

Class 12th Chemistry

In the sulphur estimation, 0.471 g of an organic compound gave 1.44g of barium sulphate The percentage of sulphur in the compound is________%. (Nearest integer)

(Atomic mass of Ba = 137u).

0 Follower 3 Views

alok kumar singh

Contributor-Level 10

Molar weight of BaSO₄ = 233 gram

233 gm of BaSO₄ has 32 gm of S content

Hence 1.44 gm of BaSO₄ has $(\frac{32 * 1.44}{233})$ g of S content = 0.1977 gm of 'S'

Weight of sulphur = 0.2 gram (the nearest)

Weight of organic sample = 0.471 gram

% of Sulphur = $\frac{0.2 * 100}{0.471} = 42.46 %$

the nearest = 42%

0 0

New answer posted

11 months ago

Class 12th Carboxylic Acids Acidity

The correct sequential addition of reagents in the preparation of 3-nitrobenzoic acid from benzene is:

0 Follower 4 Views

Vishal Baghel

Contributor-Level 10

Kindly consider the following figure

0 0

New answer posted

11 months ago

Class 12th English

There are 6 refineries, 7 depots, 9 districts. The refineries are R1, R2, R3, R4, R5, R6. The depots are D1, D2, D3, D4, D5, D6 and D7 and the districts are DR1, DR2, DR3, DR4, DR5, DR6, DR7, DR8, DR9.

Table A shows the cost of transporting one unit from refinery to depot.

Table B shows the cost of transporting one unit from depot to districts.

Table - A
	R1	R2	R3	R4	R5	R6
D1	928.2	537.2	567.8	589.9	800.1	323.4
D2	311.8	595.7	885.7	759.9	793.1	420.1
D3	451.1	0	320.1	720.1	1000.1	404.5
D4	371.1	50.1	350.1	650.4	980.1	525.3
D5	1137.3	314.5	0	1157.7	406.3	617.5
D6	617.1	516.8	756.5	1065.9	623.9	509.4
D7	644.3	299.2	537.2	1093.1	725.8	827.4

Table - B
	D1	D2	D3	D4	D5	D6	D7
DR1	571.1	205	352	159	434.5	178	337
DR2	200	337.5	291	201	0	980.7	434
DR3	100	0	275	277	850	770.5	835
DR4	0	415.7	350	760	300	560	444.7
DR5	223.5	300	440	1033	880	325	526.5
DR6	577.5	725	443.5	560	1035.3	570	530
DR7	340	410.6	886.7	0	800.7	680.5	800
DR8	627	556.5	1023	1024	759	1025.7	300
DR9	439	738	980	1031.7	1024	900	757

The minimum cost of transportation of one unit from refinery BD to any district is

0 Follower 3 Views

Payal Gupta

Contributor-Level 10

R4 → D5 → DR2

The least cost to reach to AAB is for AE. And that is BD to AE is zero.

0 0

New answer posted

11 months ago

Class 12th English

Table A shows the cost of transporting one unit from refinery to depot.

Table B shows the cost of transporting one unit from depot to districts.

Table - A
	R1	R2	R3	R4	R5	R6
D1	928.2	537.2	567.8	589.9	800.1	323.4
D2	311.8	595.7	885.7	759.9	793.1	420.1
D3	451.1	0	320.1	720.1	1000.1	404.5
D4	371.1	50.1	350.1	650.4	980.1	525.3
D5	1137.3	314.5	0	1157.7	406.3	617.5
D6	617.1	516.8	756.5	1065.9	623.9	509.4
D7	644.3	299.2	537.2	1093.1	725.8	827.4

Table - B
	D1	D2	D3	D4	D5	D6	D7
DR1	571.1	205	352	159	434.5	178	337
DR2	200	337.5	291	201	0	980.7	434
DR3	100	0	275	277	850	770.5	835
DR4	0	415.7	350	760	300	560	444.7
DR5	223.5	300	440	1033	880	325	526.5
DR6	577.5	725	443.5	560	1035.3	570	530
DR7	340	410.6	886.7	0	800.7	680.5	800
DR8	627	556.5	1023	1024	759	1025.7	300
DR9	439	738	980	1031.7	1024	900	757

The largest cost of sending one unit from any refinery to district is

0 Follower 1 View

Payal Gupta

Contributor-Level 10

If you look for large figures you would find them in both tables in D5.

the largest cost = 1157.7 + 1035.3

= 2193.00

0 0

New answer posted

11 months ago

Class 12th Chemistry

Among the following compounds I-IV, which one forms a yellow precipitate on reacting sequentially with (i) NaOH (ii) dil. HNO₃ (iii) AgNO₃?

0 Follower 10 Views

Vishal Baghel

Contributor-Level 10

Yellow precipitate is Agl (s) which only produce by structure IV

0 0

New answer posted

11 months ago

Class 12th English

Table A shows the cost of transporting one unit from refinery to depot.

Table B shows the cost of transporting one unit from depot to districts.

Table - A
	R1	R2	R3	R4	R5	R6
D1	928.2	537.2	567.8	589.9	800.1	323.4
D2	311.8	595.7	885.7	759.9	793.1	420.1
D3	451.1	0	320.1	720.1	1000.1	404.5
D4	371.1	50.1	350.1	650.4	980.1	525.3
D5	1137.3	314.5	0	1157.7	406.3	617.5
D6	617.1	516.8	756.5	1065.9	623.9	509.4
D7	644.3	299.2	537.2	1093.1	725.8	827.4

Table - B
	D1	D2	D3	D4	D5	D6	D7
DR1	571.1	205	352	159	434.5	178	337
DR2	200	337.5	291	201	0	980.7	434
DR3	100	0	275	277	850	770.5	835
DR4	0	415.7	350	760	300	560	444.7
DR5	223.5	300	440	1033	880	325	526.5
DR6	577.5	725	443.5	560	1035.3	570	530
DR7	340	410.6	886.7	0	800.7	680.5	800
DR8	627	556.5	1023	1024	759	1025.7	300
DR9	439	738	980	1031.7	1024	900	757

How many possible ways are there for sending one unit from any refinery to any district?

0 Follower 5 Views

Payal Gupta

Contributor-Level 10

Number of refineries = 6

Number of depots = 7

Number of districts = 9

Therefore, number of possible ways to send petrol from any refinery to any district is 6 * 7 * 9 = 378.

0 0

New answer posted

11 months ago

Class 12th Chemistry

The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is:

[Given: The threshold frequency of platinum is 1.3 * 10¹⁵s^-¹ and h = 6.6 * 10^-³⁴ J s.]

0 Follower 2 Views

Raj Pandey

Contributor-Level 9

$?_{0} = h υ_{0}$

$= 6.6 * 1 0^{- 34} * 1.3 * 1 0^{15} J$

^{$= 8.58 * 1 0^{- 19} J$}

0 0

Get authentic answers from experts, students and alumni that you won't find anywhere else

On Shiksha, get access to

66k Colleges
1.2k Exams
703k Reviews
1850k Answers

Community GuidelinesUser Points System

QuestionsDiscussionsTags

Need guidance on career and education? Ask our experts

Your Question

Class 12th

Questions

Discussions

Active Users

Followers

All

Discussions

Unanswered Questions

Share Your College Life Experience