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Questions Related to chemistry

Gay Lussac law gives relation between:

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. $P\,$and$\,V$

  2. $P\,$and$\,T$

  3. $V\,$and$\,T$

  4. none of these

Show answer
Correct Option: B
Explanation:

Gay Lussac's law states that pressure is directly proportional to temperature at constant volume.

Which gas law should be used to solve a gas problem in which only the pressure and temperature of a gas change?

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. Boyle's Law

  2. Ideal Gas Law

  3. Combined Gas Law

  4. Gay-Lussac's Law

Show answer
Correct Option: D
Explanation:

Gay-Lussac's law states that for a given mass and constant volume of  an ideal gas, the pressure exerted on the sides of container is directly propotional to  absolute temperature.

So, for pressure-temperature graph, we use Gay-Lussac's law.

The ratio of volumes of $H _2$ and $O _2$ liberated on electrolysis of water is

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. $1 : 2$

  2. $1 : 3$

  3. $2 : 1$

  4. $3 : 1$

Show answer
Correct Option: C
Explanation:

$H _{2}O \rightarrow H^{+} +OH^{-}$
Cathode  :  4$OH^{-} \rightarrow 2H _{2}O +O _{2}+4e^{-} $
Anode :  4$H^{+} +4e^{-} \rightarrow 2H _{2} $
The ratio of volumes of H$ _{2}$ and O$ _{2}$ is $2 : 1$.

A glass container is sealed with a gas at $0.800$ atm pressure and at $25^o$C. The glass container sustain pressure of $2$ atm. Calculate the temperature to which gas can be heated before bursting the container.

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. $432^o$C.

  2. $472^o$C.

  3. $372^o$C.

  4. $572^o$C.

Show answer
Correct Option: B
Explanation:
We have,

 $p _1=0.8$atm$,p _2=2$atm $T _1=298$k

Thus,

According to the Gas equation,

$\dfrac{p _1}{T _1}=\dfrac{p _2}{T _2}$

$\dfrac{0.8}{298}=\dfrac{2}{T _2}$

$T _2=745$k

$=472^0$C

Hence, the correct option is $\text{B}$

In the reaction ${ N } _{ 2 }+{ 3H } _{ 2 }\longrightarrow { 2H } _{ 3 }$, ratio by volume of ${ N } _{ 2 },{ H } _{ 2 }$ and $ { NH } _{ 3 }$ is $1:3:2$. This illustrates law of :

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. definite proportions

  2. multiple proportions

  3. reciprocal proportions

  4. gaseous proportions

Show answer
Correct Option: D
Explanation:

As per the Gay Lussac's law of combining volume of gases, the volumes of gaseous reactants and gaseous products bear a simple whole number ratio with each other if they are measured at same temperature and pressure.
In the reaction ${ N } _{ 2 }+{ 3H } _{ 2 }\longrightarrow { 2H } _{ 3 }$, ratio by volume of $N _2,  H _2$ and $ NH _3$ is $1:3:2$. This illustrates law of Gay Lussac's law of combining volumes of gases.

The volume of a gas is held constant while its temperature is raised. The pressure of the gas exerts on the walls of the container increases because:

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. The masses of the molecules increases

  2. Each molecule loses more kinetic energy when it strikes the wall

  3. The molecules collide with the wall with relatively greater momentum

  4. The molecules strikes the walls more often

Show answer
Correct Option: C,D
Explanation:

Volume is kept constant and temperature increased.
We have relation, $PV=nRT$
$P\propto T$
Volume constant
So, $P\propto T$ pressure increases as temperature increases.
As we know the speed or average molecular speed depend on temperature.
As temperature increases molecules collide with wall with greater force or momentum.
Also temperature increases, molecular vibrations increases. So molecule will strike with wall more often.
So option C and D.
A is incorrect because there is no change in masses of molecule when we increase temperature.

A pre-weighed vessel was filled with oxygen at $NTP$ and weighed. It was then evacuated, filled with $SO {2}$ at the same temperature and pressure and again weighed. The weight of oxygen is _____________.

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. the same as that of $SO _{2}$

  2. $\dfrac{1}{2}$ that of $SO _{2}$

  3. twice that of $SO _{2}$

  4. $\dfrac{1}{4}$ that of $SO _{2}$

Show answer
Correct Option: B
Explanation:

At constant temperature and pressure, an equal volume of gas contains an equal number of moles.


$\therefore$ Moles of $O _{2}=$ Moles of $SO _{2}$
$1\ mole\ O _{2}=32\ g$
$1\ mole\ SO _{2}=64\ g$
$\therefore wt$ of $O _2=\dfrac{1}{2}$ that of $SO _{2}$
Option $B$ is correct.

A certain vessel $X$ has water and nitrogen gas at a total pressure of 2 $atm$ at 300 $K$. All the contents of the vessel are transferred to another vessel $Y$ having half the capacity of the vessel $X$.The pressure of ${N} _{2}$ in this vessel was 3.8 $atm$ at 300 $K$.The vessel $Y$ is heated to 320 $K$ and the total pressure observed was 4.32 $atm$. The pressure of ${N} _{2}$ at 320 $K$ is :

[Assume that the volume occupied by the gases in the vessel is equal to the volume of the vessel.]

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. 4.0

  2. 4.05

  3. 5.05

  4. 1.05

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Correct Option: B

Law of definite proportions when expressed in terms of volumes becomes:

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. Dalton's Law

  2. Berzelius hypothesis

  3. Gay-Lussac's Law

  4. Avogadro's Law

Show answer
Correct Option: C
Explanation:

Law of definite proportions: It states that a given chemical substance (compound) always contains the same elements combined in a fixed proportion by weight. It is also called the law of constant composition.
The law of combining volumes was given by Gay Lussac in 1808. It is applicable only to a gaseous reaction. According to this law, gases combine or are produced in a chemical reaction they do so in a simple ratio by volume provided all gases are at same temperature and pressure. So, the law of definite proportions when expressed in terms of volumes becomes 'Gay-Lussac's Law'. 
Avogadro's law states that 'equal volumes of all gases, at the same temperature and pressure, have the same number of molecules'.
According to Berzelius hypothesis, equal volumes of all gases contain an equal number of atoms under similar conditions of temperature and pressure.

For which of the following reactions, is Gay Lussac's law not applicable?

chemistry states of matter: gaseous and liquid states gay lussac's law gas laws states of matter

  1. Formation of $HI$ from its constituents

  2. Formation of $NH _3$ from its constituents

  3. Formation of $CO _2$ from its constituents

  4. Formation of $SO _3$ from $SO _2$ and $O _2$

Show answer
Correct Option: C
Explanation:

Gay Lussac's law not applicable to formation of $CO _{2}$ from its constituents as carbon and oxygen exist in different physical states.