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Questions Related to chemistry

Which one is correct about  Gay-Lussac's law?

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

  1. V/T $=$ k

  2. P/T $=$ k

  3. PV $=$ k

  4. $P _T=P _1+P _2+P _3$

  5. PT $=$ k

Show answer
Correct Option: B
Explanation:

According to Gay-Lussac's Law :


$\displaystyle \dfrac {P}{T}= k $ 

At constant volume, the pressure of a given mass of a gas varies directly with the temperature.

$\displaystyle P \propto T $ (V and n constant)

Hence, the correct option is B.

Which one proposes a relationship between the combining volumes of gases with respect to the reactants and gaseous products.

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

  1. Avogadro's number

  2. $P _1V _1=P _2V _2$

  3. $V _1T _2=V _2T _1$

  4. Dalton's Theory

  5. Gay-Lussac's Law

Show answer
Correct Option: E
Explanation:

Gay-Lussac's Law proposes a relationship between the combining volumes of gases with respect to the reactants and gaseous products. According to this law, when gases react together to produce gaseous products, the volumes of reactants and products bear a simple whole number ratio with each other, provided volumes are measured at same temperature and pressure.

Gay Lussac's Law of combining volumes is applicable for combustion of carbon.

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

  1. True

  2. False

Show answer
Correct Option: B
Explanation:
Gay Lussac's Law of Combining Volumes. Gay Lussac's Law of Combining Volumes states that whengases react, they do so in volumeswhich bear a simple ratio to one another, and to the volume of the product(s) formed if gaseous, provided the temperature and pressure remain constant.

The specific heat of a bivalent metal is 0.16. The approximate equivalent mass of the metal will be:

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

  1. 40

  2. 20

  3. 80

  4. 10

Show answer
Correct Option: B
Explanation:

atomic weight = $\dfrac{6.4}{specific heat}$


atomic weight = 40
equivalent weight = $\dfrac{40}{2}$ (bivalent)

equivalent mass = 20

Equal volumes of different gases at any definite temperature and pressure have:

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

  1. equal weights

  2. equal masses

  3. equal densities

  4. equal number of moles

Show answer
Correct Option: D
Explanation:

At equal volume of different gases at any definite temperature and pressure have equal no. of particles.

hence, equal number of moles.

Four flasks of 1 litre capacity each arc separately filled with gases $H _2, He, O _2$ and $O _3$. At the same temperature and pressure the ratio of the number of atoms of these gases present in different flasks would be: 

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

  1. 1 : 1 : 1 : 1

  2. 2 : 1 : 2 : 3

  3. 1 : 2 : 1 : 3

  4. 3 : 2 : 2 : 1

Show answer
Correct Option: A
Explanation:

Ans ; A

Here in this question 4 different  types of gasses are filled in same volume of flasks i.e. all 4 types of gasses have same number of molecules.
THe ratio of number of atoms of these gasses present in different flasks would be = 1:1:1:1

The volume occupied by 0.01 moles of helium gas at STP is:

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

  1. $0.224  l$

  2. $22.4  l$

  3. $2240  l$

  4. $2.24  l$

Show answer
Correct Option: A
Explanation:

As 1 mole of a gaseous substance occupies 22.4 litre ($22.4 l =$ gram molar volume)
Volume occupied $=GMV \times 0.01$( gram molar volume )

Hence, volume occupied $= 22.4\times0.01$
                                            $= 0.224l$

A mixture of CO and $CO _2$ has a density of $1.5 g/l $ at $27^o$C and $760$ mm pressure. If $1\ l$ of the mixture is exposed to alkali, what would be the pressure of the remaining gas at the same volume and temperature?

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

  1. $533$ mm

  2. $473$ mm

  3. $335$ mm

  4. $595$ mm

Show answer
Correct Option: C
Explanation:

The given density$=d=\dfrac{m}{volume}$ …….$(1)$


so the given mass is a mixture of CO & $CO _2$

$m=n _{CO}\times 28+n _{CO _2}\times 44$

${$ using no. of moles$=\dfrac{mass}{mol. mass}}$

Also using $PV=nRT$
$V=\dfrac{(n _{CO}+n _{CO _2})RT}{P}$

Putting in $(1)$
$1.5=\dfrac{n _{CO}\times 28+44\times n _{CO _2}}{{(n _{CO _2}+n _{CO})\times 0.082\times 300}}$ $[{760$mm$=1$atm$}, P=1atm]$

$1.5=\dfrac{28n _{CO}+44n _{CO _2}}{24.6(n _{CO}+n _{CO _2})}$


$\Rightarrow 36.9(n _{CO}+n _{CO _2})=28n _{CO}+44n _{CO _2}$

$9n _{CO}=7n _{CO _2}$

After the reaction with alkali, all $CO _2$ will be used so the remaining pressure will be of $CO$.

$P _{CO _2}=\dfrac{n _{CO}}{n _{CO}+n _{CO _2}}\times P _{Total}$

$=\dfrac{n _{CO}}{n _{CO}+\dfrac{9}{7}n _{CO}}$

$=\dfrac{7}{16}P _{Total}=\dfrac{7}{16}\times 760$

$ \approx 335$ mm
Option C.

Chlorofluorocarbons such as $CCl _3F\ (M=137.5)$ and $CCl _2F _2\ (M=121)$ have been linked to ozone depletion in Antarctica. As of $2004$, these gases were found in $275$ and $605$ parts per trillion $(10^{12})$, ny volume. What are the concentrations of these gases under conditions typical of Antarctica stratosphere ($200\ K$ and $0.08\ atm$)? $(R=0.08\ l-atm/K-mol)$   

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

  1. $[CCl _3F]=1.375\times 10^{-12}\ mol\ l^{-1}$,
    $[CCl _2F _2]=3.025\times 10^{-12}\ mol\ l^{-1}$

  2. $[CCl _3F]=2.75\times 10^{-14}\ mol\ l^{-1}$,
    $[CCl _2F _2]=6.05\times 10^{-14}\ mol\ l^{-1}$

  3. $[CCl _3F]=2.75\times 10^{-10}\ mol\ l^{-1}$,
    $[CCl _2F _2]=6.05\times 10^{-10}\ mol\ l^{-1}$

  4. $[CCl _3F]=1.375\times 10^{-13}\ mol\ l^{-1}$,
    $[CCl _2F _2]=3.025\times 10^{-12}\ mol\ l^{-1}$

Show answer
Correct Option: A
Explanation:

$CCl _3F(mw)=133.5$
$CCl _2F _2(mw)=121$
By given data first we calculate density of solution
$\dfrac {P}{S}=\dfrac {RT}{Mw}\quad R=0.08\quad T=200$
$P=0.08$
for $CCl _3F-S(CCl _3F)=\dfrac {0.08\times 133.5}{0.08\times 200}$
$S=0.6875$
for $CCl _2F _2=\dfrac {0.08\times 121}{0.08\times 200}$
$=0.605$
given data in $(PPt)$
$10^{12}\ gm$ solution contains $=175\ gm$
$10^{3}\ gm$ solution contains $=\dfrac {275}{10^{12}}\times 10^3$
Mass $=275\times 10^{-9}\ gm$
find the volume $d=\dfrac {M}{v}$
$v=\dfrac {1000}{0.6785}=1454.5$
Molarity of $CCl _3F=\dfrac {275\times 10^{-9}}{137.5\times 1454.5}$
$=1.37\times 10^{-12}$
Similarly for $CCl _2F _2$
$10^{12}\ gm$ solution certain $=605$
$10^{3}\ gm$ solution certain $=\dfrac {605}{10^{12}}\times 10^3$
Mass $=605\times 10^{-9}$
$d=\dfrac {m}{v}\quad v=\dfrac {m}{v}=\dfrac {1000}{605}$
$v=1652.89$
molarity $=\dfrac {605\times 10^{-9}}{121\times 1652.89}$
$M=3.02\times 10^{-12}\ mol\ l^3$

A quantity of $4$g of oxygen occupies $10$ L at a particular pressure and temperature. If the pressure of gas is doubled and absolute temperature is halved, in order to maintain constant volume.

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

  1. $3$ g gas should be removed from container

  2. $3$ g gas should be added in the container

  3. $16$ g gas should be added in the container

  4. $12$ g gas should be added in the container

Show answer
Correct Option: D
Explanation:

Given that,
$m _1=4g$ $V _1=10L$,$P _1=P$,$T _1=T$

$m _2=?$, $V _2=10L$,$P _2=2P$, $T _2=\dfrac{T}{2}$

We know that,

$PV=\dfrac{m}{M}RT$

At constant volume, V

$\dfrac{P _1}{P _2}=\dfrac{m _1RT _1}{m _2RT _2}$

$\dfrac{P}{2P}=\dfrac{4\times T}{m _2\times \dfrac{T}{2}}$


$\dfrac{1}{2}=\dfrac{8}{m _2}$

$m _2=16$g

Mass of gas added into container$=16-4=12$g.