Batteries

Trending Questions

Write the formulae for Baking soda and calculate the molecular mass for Baking soda

Does cell potential have to be positive

Q. In a lead storage battery,

d i l . H_{2} S O_{4}

is used as an electrolyte and consumed during redox reactions. It can be refilled many times.

True
False

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Main defects in a simple voltaic cell are local action and polarisation.

True
False

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Q. Urea

(H_{2} N C O N H_{2})

is manufactured by passing

C O_{2} (g)

through ammonia solution followed by crystallization.

C O_{2}

for the above reaction is prepared by combustion of hydrocarbon. If combustion of

236 k g

of a saturated hydrocarbon

(C_{n} H_{2 n + 2})

produces as much

C O_{2}

as required for production of

999.6 k g

urea then molecular formula of hydrocarbon is:

$C_{10} H_{22}$
$C_{12} H_{26}$
$C_{13} H_{28}$
$C_{8} H_{18}$

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Which cell gives a constant voltage throughout its life and why?

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Q. Two elements

X

and

Y

have atomic mass

75

and

16

respectively. They combine to give a compound having

75.8 %

X

. The empirical formula of the compound is:

$X Y$
$X_{2} Y$
$X_{2} Y_{2}$
$X_{2} Y_{3}$

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Q. Statement 1:
Every spontaneous redox reaction can be used as the basis of an electrochemical cell, yet every such electrochemical cell is not suitable for commercial purposes.

Statement 2: Electrochemical cells using salt bridges have high internal resistance and they lack the compactness and ruggedness for portability.

Statement 1 is True, Statement 2 is False.
Statement 2 is True, Statement 1 is False
Both the statements are True.
Both the statements are False.

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A certain alkaloid has $70.8 % C, 6.2 % H$ and $4.1 %$ of N and rest O. The empirical formula is

$C_{20} H_{21} N O_{4}$
$C_{20} H_{20} N O_{4}$
$C_{21} H_{20} N O_{3}$
$C_{20} H_{10} N O_{3}$

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A mixture of equal amounts of calcium carbonate and sodium carbonate was heated till there is no further loss in weight. If the gaseous product obtained occupied a volume of $5.6$ L at STP, find out the initial weight of the mixture.

$100$ g
$50$ g
$75$ g
$25$ g

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Q. What is the ratio of the empirical formula mass to the molecular formula mass of benzene?

$1 : 6$
$2 : 3$
$6 : 1$
$3 : 2$

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Q. Mercury cell gives a constant potential.

True
False

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Q. Statement 1: Primary cell can be recharged by passing an electric current through them.
Statement 2: Secondary cells are those in which the energy produced from the combustion of fuels is directly converted into electrical energy.

Statement 1 is True, Statement 2 is False
Statement 2 is True, Statement 1 is False
Both the statements are True
Both the statements are false

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Q. The molecular mass of butyric acid was determined by experiment to be 88

g m o l^{- 1}

. What is the molecular formula?
Empirical formula=.

C_{2} H_{4} O

$C_{4} H_{8} O_{2}$
$C_{2} H_{4} O$
$C H_{4} O$
$C_{2} H_{4} O_{2}$

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Q. A given sample of pure compound contains

9.81 g

Z n

1.8 \times 10^{23}

atoms of chromium and 0.60 mol of oxygen atoms. What is the simplest formula?

$Z n C r_{2} O_{7}$
$Z n C r_{2} O_{4}$
$Z n C r O_{4}$
$Z n C r_{2} O_{6}$

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Define the following term:

Percentage composition of a compound

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180 g

of a compound containing

C, H

and

O

reacts fully with excess oxygen and produces

264 g

C O_{2}

and

108 g

H_{2} O

. If the ratio of molar mass of the compound to the empirical formula mass is

6

then find the molecular formula of given compound.

$C H_{2} O$
$C_{6} H_{12} O_{6}$
$C_{12} H_{24} O_{12}$
$C_{42} H_{84} O_{42}$

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Q. A battery may have one or more than one cell connected in series.

True
False

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Q. In a compound

C, H

N

are present in the ratio of

18 : 2 : 7

by weight. The empirical formula of the compound is:

$C_{2} H_{6} N_{2}$
$C_{3} H_{4} N$
$C_{2} H_{8} N_{2}$
$C_{9} H_{12} N_{3}$

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The ratio of the mass of C-12 atom to that of an atom of element $X$ (whose atomicity is four) is 1 : 9. Themolecular mass of element $X$ is

$480 g m o l^{- 1}$
$432 g m o l^{- 1}$
$72 g m o l^{- 1}$
$108 g m o l^{- 1}$

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Q. 0.0416 mol of a carbohydrate having an empirical formula

C H_{2} O

contains

1 g

of hydrogen. The molecular formula of the carbohydrate is:

$C_{12} H_{24} O_{12}$
$C_{6} H_{12} O_{6}$
$C_{12} H_{24} O_{11}$
$C_{8} H_{14} O_{8}$

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Q. The empirical formula of a compound is

C H_{2} O

. If 0.0833 moles of the compound contains 1 g of hydrogen, find the molecular formula of the compound.

$C_{5} H_{10} O_{5}$
$C_{6} H_{12} O_{6}$
$C_{4} H_{8} O_{4}$
$C_{3} H_{6} O_{3}$

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Q. In the following question, a statement of assertion (A) is followed by a statement of reason (R):
(A): The ratio of molecular formula mass and empirical formula mass must be a natural number.
(R): The empirical formula can never be the same as the molecular formula.

If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (a)
If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (b)
If Assertion is true statement but Reason is false, then mark (c)
If both Assertion and Reason are false statements, then mark (d)

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Q. The empirical formula of a gaseous fluorocarbon is

C F_{2}

. At a certian temperature and pressure, a 1 L volume hold 8.95 g of this fluorocarbon. Under the same conditions, 1 L volume holds only 1.70 g gaseous

F_{2}

. Thus, fluorocarbon is_______.
(F = 19)

$C F_{2}$
$C_{2} F_{4}$
$C_{3} F_{6}$
$C_{4} F_{8}$

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Q. Sodium and oxygen combine to form two compounds of which one is

N a_{2} O

. The percentage of sodium in the other compound is 59%. Calculate the molecular weight (u) of the compound.

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Q. 0.242 g sample of K is heated in the presence of oxygen gas. This resulted in the formation of 0.440 g of a crystalline compound. What is the formula of this compound?

$K O$
$K_{2} O$
$K O_{2}$
$K O_{3}$

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Q. Urea

(H_{2} N C O N H_{2})

is manufactured by passing

C O_{2} (g)

through ammonia solution followed by crystallization.

C O_{2}

for the above reaction is prepared by combustion of hydrocarbon. If combustion of

236 k g

of a saturated hydrocarbon

(C_{n} H_{2 n + 2})

produces as much

C O_{2}

as required for production of

999.6 k g

urea then molecular formula of hydrocarbon is:

$C_{10} H_{22}$
$C_{12} H_{26}$
$C_{13} H_{28}$
$C_{8} H_{18}$

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Q. What is the empirical formula of vanadium oxide, if

2.74 g

of the metal oxide contains

1.53 g

of metal?

$V_{2} O_{3}$
$V O$
$V_{2} O_{5}$
$V_{2} O_{7}$

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In the body of a healthy adult human, the most prevalent elements by mass are Oxygen $(O)$ $(61.4 %)$ , Carbon $(C)$ $(22.9 %)$ , Hydrogen $(H)$ $(10 %)$ , and Nitrogen $(N)$ $(2.6 %)$ . If all ${}^{1}H$ atoms are switched out for ${}^{2}H$ atoms, a $75 kg$ human will acquire the following amount of weight:

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1.615 g of anhydrous $Z n S O_{4}$ was places in moist air. After a few days, its mass was found to be 2.875g. The molecular formula for hydrated zinc sulphate is

$Z n S O_{4} .2 H_{2} O$
$Z n S O_{4} .5 H_{2} O$
$Z n S O_{4} .7 H_{2} O$
$Z n S O_{4} .10 H_{2} O$

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