MCQ 11 Mark
Avogadro's law finds an application in the determination of :
- A
- ✓
Molecular weights of gases.
- C
Molecular formula of certain gaseous compoun.
- D
AnswerCorrect option: B. Molecular weights of gases.
Avogadro's law finds an application in the determination of molecular weights of gases.
View full question & answer→MCQ 21 Mark
If $3.01 \times 10^{20}$ molecules are removed from $98 \ \ce{mg}$ of $\ce{H_2SO_4}$, then number of moles of $\ce{H_2SO_4}$ left are:
- ✓
$0.5 \times 10^{-3}$ mol.
- B
$0.1 \times 10^{-3}$ mol.
- C
$9.95 \times 10^{-3}$mol.
- D
$1.66 \times 10^{-3}$mol.
AnswerCorrect option: A. $0.5 \times 10^{-3}$ mol.
Number of moles $\ce{H_2SO_4}$ in $98g$ of $\ce{H_2SO_4}$
$=\frac{98\times10^{-3}\text{g}}{98}=10^{-3}\text{moles}$
Number of moles $\ce{H_2SO_4}$ removed
$=\frac{3.01\times10^{20}}{6.02\times10^{23}}=\frac{1}{2}\times10^{-3}$
$=0.5\times10^{-3}\text{mol}$
Number of moles $\ce{H_2SO_4}$ left
$= 1 \times 10 ^{-3} - 0.5 \times 10^{-3} $
$= 0.5 \times 10^{-3}$ moles.
View full question & answer→MCQ 31 Mark
A certain metal sulphide, $\ce{MS_2}$, is used extensively as a high temperature lubricant. If $\ce{MS_2}$ is $40.06\%$ by mass of sulphur, metal $M$ has atomic mass :
- A
$160$ amu
- B
$64$ amu
- C
$40$ amu
- ✓
$96$ amu
AnswerCorrect option: D. $96$ amu
Molecular weight of $\ce{MS_2 = 2S + M}$
$\frac{64}{\text{M}+64}=0.4006$
$\therefore\text{M}=96$
View full question & answer→MCQ 41 Mark
A solution is prepared by dissolving $5.64g$ of glucose in $60g$ of water. Calculate the mass percent of glucose.
- ✓
$8.59\%$
- B
$6.85\%$
- C
$9.34\%$
- D
$3.59\%$
AnswerCorrect option: A. $8.59\%$
$\text{Mass percent of glucose}=\frac{\text{mass of glucose }}{\text{mass of solutio}}\times100$
$=\frac{5.64}{(5.64+60)}\times100$
View full question & answer→MCQ 51 Mark
In chulhas, gaps are left between the logs :
- A
To decrease the ignition temperature of the fuel.
- ✓
To allow the air to enter and facilitate fuel burning.
- C
To cut off the supply of air.
- D
AnswerCorrect option: B. To allow the air to enter and facilitate fuel burning.
It is important to keep gaps between the logs in chulhas to allow the air to enter and facilitate fuel burning.
View full question & answer→MCQ 61 Mark
Given that, the abundances of isotopes $^{54}\ce{Fe}, ^{56} F_4 $ and $^{57} \ce{Fe}$ are $5\%, 90\%$ and $5\%$ respectively, the atomic mass of $\ce{Fe}$ is :
- A
$55.85$
- ✓
$55.95$
- C
$55.75$
- D
$56.05$
AnswerCorrect option: B. $55.95$
View full question & answer→MCQ 71 Mark
Which of the following expression of concentration of a solution is independent of temperature?
Answer$\text{Molality}=\frac{\text{number of moles of solute }}{\text{mass of solvent in kilograms }}$
Since mass is unaffected by the change in temperature, hence molality is independent of temperature.
View full question & answer→MCQ 81 Mark
A student performs a titration with different burettes and finds titre values of $25.2\ mL, 25.25\ mL$ and $25.0\ mL.$ The number of significant figures in the average titre value is :
View full question & answer→MCQ 91 Mark
What is the percentage by weight of sulphuric acid if $13g$ of $\ce{H_2SO_4}$ is dissolved to make $78g$ of solution?
- A
$13.2\%$
- B
$14.28\%$
- C
$20\%$
- ✓
$16.6\%$
AnswerCorrect option: D. $16.6\%$
Weight of sulphuric acid $= 13g$
Weight of solution $= 78g$
$\therefore\frac{\text{w}}{\text{W}}\%=\frac{13}{78}\times100=16.6\%$
View full question & answer→MCQ 101 Mark
The relative atomic mass of naturally occurring chlorine is not a whole number. What is the reason for this ?
- ✓
Chlorine atoms can have different number of neutrons.
- B
Naturally occurring chlorine cannot be obtained pure.
- C
- D
The mass of the electrons has been included.
AnswerCorrect option: A. Chlorine atoms can have different number of neutrons.
The relative atomic mass of an element is the average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance.
Chlorine has two isotopes available in Nature.
One has At.mass $= 35$ which forms roughly $75\%$ of the naturally available Chlorine.
Another has At.mass $= 37$ which forms roughly $25\%$ of the naturally available Chlorine.
So they have fractional atomic mass.
View full question & answer→MCQ 111 Mark
What will be the ratio of $\ce{Cl}^{35}$ and $\text{Cl}^{37}$ respectively in ordinary chlorine if the atomic weight of chlorine is $35.5$
- A
$1 : 3$
- ✓
$3 : 1$
- C
$1 : 2$
- D
$2 : 1$
AnswerCorrect option: B. $3 : 1$
Using average molcular mass formula :
$x(35) + (1−x) (37) = 35.5$
$x = 0.75$
$1 − x = 0.25$
$\frac{0.75}{0.25}=3:1$
View full question & answer→MCQ 121 Mark
$800 g$ of a $40\%$ solution by weight was cooled. $100g$ of solute was precipitated. The percentage composition of remaining solution is:
- ✓
$31.4\%$
- B
$20.0\%$
- C
$23.0\%$
- D
$24\%$
AnswerCorrect option: A. $31.4\%$
Solutepresentin $800g$ solution $=800\times\frac{40}{100}=320\text{g}$
Soluteprecipitated $= 100g$
Soluteleft $= 220g$
$\therefore$ Totalweightofsolution $= 800 − 100 = 700g$
$700g $ solution has solute $= 220$
$100g$ solution has solute $=\frac{220}{700}\times100=31.43\%$
View full question & answer→MCQ 131 Mark
Who performed the gold foil experiment?
AnswerRutherford's Gold foil experiment proved the existence of a small massive centre to atoms, which was later known as the nucleus of an atom.
Ernest Rutherford, Hans Geiger and Ernest Marsden carried out their Gold foil experiment to observe the effect of alpha particles on the matter.
View full question & answer→MCQ 141 Mark
Which law is not applicable for a nuclear reaction where large amount of energy is released?
- ✓
Law of conservation of mass
- B
Law of definite proportion
- C
Law of multiple proportion
- D
AnswerCorrect option: A. Law of conservation of mass
The law implies that during any chemical reaction, nuclear reaction, or radioactive decay in an isolated system, the total mass of the reactants or starting materials must be equal to the mass of the products. Mass conservation remains correct if energy is not lost but if energy is released in a nuclear reaction, the law of conservation of mass does not hold any good.
View full question & answer→MCQ 151 Mark
India's uranium supply comes mainly from the Jaduguda mines in :
MCQ 161 Mark
Mass number is denoted by :
AnswerThe mass number $(A)$ is the number of nucleons, which is the total number of protons and neutrons in the nucleus of an atom.
View full question & answer→MCQ 171 Mark
Which of the following reactions is not correct according to the law of conservation of mass.
- A
$2{\ce{Mg(s)}}+{O}_2{(g)}\rightarrow2{\ce{Mg}{O(s)}}$
- ✓
$\text{C}_3\text{H}_8\text{(g)}=\text{O}_2\text{(g)}\rightarrow\text{CO}_2\text{(g)}=\text{H}_2\text{O}\text{(g)}$
- C
$\text{P}_4\text{(s)}=5\text{O}_2\text{(g)}\rightarrow\text{P}_4\text{O}_{10}\text{(s)}$
- D
$\text{CH}_4\text{(g)}=2\text{O}_2\text{(g)}\rightarrow\text{CO}_2\text{(g)}+2\text{H}_2\text{O}\text{(g)}$
AnswerCorrect option: B. $\text{C}_3\text{H}_8\text{(g)}=\text{O}_2\text{(g)}\rightarrow\text{CO}_2\text{(g)}=\text{H}_2\text{O}\text{(g)}$
Since the reaction is not balanced, hence, mass of reactants and products are different. It is against the law of conservation of mass.
View full question & answer→MCQ 181 Mark
When an inflated tyre bursts, the air escaping out will :
- A
- ✓
- C
Not undergo any change in its temperature
- D
View full question & answer→MCQ 191 Mark
What is the mass of the solvent present in $200g$ of $25\%\ (w/ W) $ calcium hydroxide solution?
- ✓
$150g$
- B
$125g$
- C
$175g$
- D
$100g$
AnswerCorrect option: A. $150g$
Given that Mass of solution $= 200g$ and let mass of solute $= x$
Now, mass of the solute can be calculated as follow : $25=\frac{\text{x}}{200}\times100$
Thus, $x =$ mass of solute $= 50g$
Therefore mass of solvent $=$ mass of solution $-$ mass of solute $= 200 - 50 = 150g$
View full question & answer→MCQ 201 Mark
Dalton’s atomic theory was based on :
- ✓
Law of chemical combination.
- B
- C
- D
AnswerCorrect option: A. Law of chemical combination.
When substances react, they do so by following certain laws. These laws are called the laws of chemical combination. Law of conservation of mass, the law of definite proportions, the law of multiple proportions, Gay lussac's law of gaseous volumes, Avogadro's law. These formed the basis of Dalton's atomic theory of matter.
View full question & answer→MCQ 211 Mark
Which of the following statements is/ are correct regarding significant figures?
MCQ 221 Mark
$1.020g$ of metallic oxide contains $0.540g$ of the metal. If the specific heat of the metal, $M$ is $0.216\ \ce{ cal deg ^{-1} g^{-1}}$. The molecular formula of its oxide is:
- A
$\ce{MO}$
- ✓
$\ce{M_2O_3}$
- C
$\ce{M_2O_4}$
- D
$\ce{M_2O}$
AnswerCorrect option: B. $\ce{M_2O_3}$
View full question & answer→MCQ 231 Mark
What will be the molality of the solution containing $18.25g$ of $\text{HCl }$ gas in $500g$ of water?
Answer$\text{Molility}=\frac{\text{No. of moles of solute}}{\text{Mass of solvent in kg}}$
$\text{no. of moles}=\frac{18.25}{36.5}=0.5$
$\text{Molality}=\frac{0.5}{0.5}=1\text{m}$
View full question & answer→MCQ 241 Mark
Addition of $6.65 \times 10^4$ and $8.95 \times 10^3,$ in terms of scientific notation will be :
- ✓
$7.545 \times 10^4$
- B
$75.45 \times 10^3$
- C
$754.5 \times 10^2$
- D
$75.45 \times 10^0$
AnswerCorrect option: A. $7.545 \times 10^4$
View full question & answer→MCQ 251 Mark
$\ce{Na_2SO_3}⋅\ce{xH_2O}$ has $50\%\ \ce{H_2O}$ by mass. Hence $, x$ is :
AnswerMolecular mass of $\ce{Na_2SO_3}⋅ \ce{x H_2 O = 126 + 18x}$
Hence, $\frac{18\text{x}}{126+18\text{x}}=0.5{\text{(given)}}$
$\therefore\text{x}=7$
View full question & answer→MCQ 261 Mark
The matter is neither created nor destroyed during any physical or chemical change. This statement is of the :
- A
Law of constant proportion.
- ✓
Law of conservation of mass.
- C
Law of reciprocal proportion.
- D
Law of multiple proportion.
AnswerCorrect option: B. Law of conservation of mass.
The law of conservation of mass states that "the matter is neither created nor destroyed during any physical or chemical change".
The Law of conservation of Mass states that matter can be changed from one form into another, mixtures can be separated or made, and pure substances can be decomposed, but the total amount of mass remains constant. The total mass of the universe is constant within measurable limits.
View full question & answer→MCQ 271 Mark
The mass of hydrogen at $\text{STP},$ that is present in a vessel which can hold $4$ grams of oxygen under similar conditions, is :
- A
$1gm$
- B
$0.5gm$
- ✓
$0.25gm$
- D
$0.125gm$
AnswerCorrect option: C. $0.25gm$
Equal volumes of different gases at $\text{STP}$ contains an equal number of moles.
$4g$ oxygen corresponds to $\frac{4}{32}=0.125$ mole.
This is also equal to the number of moles of hydrogen. $1$ mole of hydrogen corresponds to $2gm.$
Hence, $0.125$ mole will correspond to $2 \times 0.125 = 0.25gm.$
View full question & answer→MCQ 281 Mark
What is $\%$ composition of a substance?
AnswerCorrect option: C. $\%$ of the total mass of a substance.
The percent composition of a component in a compound is the percent of the total mass of the compound that is due to that component.
View full question & answer→MCQ 291 Mark
A compound was found to contain $5.37\%$ nitrogen. What is the minimum molecular weight of compound ?
- A
$26.07$
- B
$2.607$
- ✓
$260.7$
- D
AnswerCorrect option: C. $260.7$
$5.37g$ of $N$ in $100g$ compound.
$14\text{g}\text{N}=\frac{100\times14}{5.37}=260.7\text{g}\text{ compound}$
Which is the minimum molecular wt as it should have at least one $N.$
View full question & answer→MCQ 301 Mark
The percentage value of nitrogen in urea is about :
AnswerThe formula of urea is $\ce{NH_2\ CONH_2}$
$\ce{W_N} = 28$
$\ce{W_C} = 12$
$\ce{W_O} = 16$
$\ce{W_H} = 4$
In $60g$ urea, $\ce{W_N} = 28g$
$100g$ urea, $\ce{W_N}$ is $=\frac{28}{60}\times100=46\%$
View full question & answer→MCQ 311 Mark
$1u= ?$
- A
The mass of one atom of the carbon $-12$ isotope
- B
$\frac{1}{12}^\text{th}$ the mass of one atom of the carbon $-16$ isotope
- ✓
$\frac{1}{12}^\text{th}$ the mass of one atom of the carbon $-12$ isotope
- D
The mass of one atom of the carbon $-16$ isotope
AnswerCorrect option: C. $\frac{1}{12}^\text{th}$ the mass of one atom of the carbon $-12$ isotope
$1u = \frac{1}{12}^\text{th}$ the mass of one atom of the carbon $-12$ isotope.
View full question & answer→MCQ 321 Mark
An organic compound containing $C$ and $H$ has $92.3\%$ of carbon, its empirical formula is :
- ✓
$\ce{CH}$
- B
$\ce{CH_3}$
- C
$\ce{CH_2}$
- D
$\ce{CH_4}$
AnswerCorrect option: A. $\ce{CH}$
| Element |
$\%$ |
$\%$ atomic weight |
Simplest ratio |
| $C$ |
$92.3$ |
$\frac{92.3}{12}=7.69$ |
$\frac{7.69}{7.69}=1$ |
| $H$ |
$7.7$ |
$\frac{7.7}{1}=7.70$ |
$\frac{7.70}{7.69}=1$ |
$\therefore$ Empirical formula $= \ce{CH}$ View full question & answer→MCQ 331 Mark
Two students performed the same experiment separately and each one of them recorded two readings of mass which are given below. Correct reading of mass is $3.0g$. On the basis of given data, mark the correct option out of the following statements.
|
Student
|
Readings
|
|
|
$(i)$ |
$(ii)$ |
| $A$ |
$3.01$ |
$2.99$ |
| $B$ |
$3.05$ |
$2.95$ |
- A
Results of both the students are neither accurate nor precise.
- ✓
Results of student $A$ are both precise and accurate.
- C
Results of student $B$ are neither precise nor accurate.
- D
Rsults of student $B$ are both precise and accurate.
AnswerCorrect option: B. Results of student $A$ are both precise and accurate.
Average of redings of student $\text{A}=\frac{3.01+2.99}{2}=3.00$
Average of readings of student $\text{B}=\frac{3.05+2.95}{2}=3.00$
Correct reding $= 3.0$
For both the students, average value is close to the correct value.
Hence, readings of both are accurate. But readings of student $A$ are also close to each other $($differ only by $0.02)$ and also close to the average value, hence readings of $A$ are also precise.
But readings of $B$ are not close to each other $($differ by $0.1)$ and hence are not precise. Thus, results of student $A$ are both precise and accurate.
View full question & answer→MCQ 341 Mark
Which term describes the mass of $6.023 \times 10^{23}$ representative particles?
AnswerMolar mass of a compound describes the total mass of $6.023 \times 10^{23}$ atoms or particles of the compound.
Ex : Molar mass of $\ce{H_2 = 2g}$
View full question & answer→MCQ 351 Mark
Photo $-$ electric cell is not used in :
- A
- ✓
- C
Reproduction of sound in cinema.
- D
Automatic switching of street lightening circuits.
AnswerThe exposure meter instead of photo electric cell is used in camera to know the correct time of exposure.
View full question & answer→MCQ 361 Mark
Branch of chemistry deals with structure of matter, the energy changes and theories, laws and principles that explain the transfer motion of matter for one form to another is known as :
AnswerPhysical chemistry deals with structure of matter, the energy changes and theories, laws and principles which explains the transfer motion of matter from one form to another.
View full question & answer→MCQ 371 Mark
If $500\ mL$ of a $5M$ solution is diluted to $1500\ mL,$ what will be the molarity of the solution obtained?
- A
$1.5M$
- ✓
$1.66M$
- C
$0.017M$
- D
$1.59M$
AnswerCorrect option: B. $1.66M$
If $500\ ml$ of solution is diluted to $1500\ ml$ of solution.
The morality can be calculated by the formula $M_1V_1 = M_2V_2$
Whereas $M_1 = 5M, V_1 = 500, V_2 = 1500, M_2 =?$
Here we have to find $M_2$.
By pitting values in the formula
$5 \times 500 = 1500 \times M_2$
$\text{M}_2=\frac{2500}{1500}$
$= 1.66M$
Hence the morality is $1.66M$
View full question & answer→MCQ 381 Mark
Atomic mass of an element is :
- A
Actual mass of one atom of the element
- ✓
Average mass of an atom of different atoms of the element
- C
- D
AnswerCorrect option: B. Average mass of an atom of different atoms of the element
Atomic mass is an average mass of different atoms of an element, as most elements have different isotopes. Atomic mass is usually not a whole number. It can be a fraction.
View full question & answer→MCQ 391 Mark
The mass of a sand and powdered mixture along with a beaker is $56g$. If the mass of the dried mixture is $20g,$ find the $\%$ composition of the mixture in $100g\ ? \ ($weight of beaker $= 20g).$
- A
$20\%$
- B
$36\%$
- ✓
$55\%$
- D
$60\%$
AnswerCorrect option: C. $55\%$
Mass of beaker $= 20g$
Mass of mixture $+$ beaker $= 56g$
Mass of mixture $= 56 - 20 = 36g$
Mass of washed and dried sand $= 20g$
$100g$ of mixture contains $=\frac{20}{36}\times100=55\%$ of sand.
View full question & answer→MCQ 401 Mark
If $1 L$ of $O_2$ at $15^\circ C$ and $750\ mm$ pressure contains $N$ molecules, the number of molecules in $2 L$ of $\ce{SO_2}$ under the same conditions of temperature and pressure will be :
- A
$\frac{\text{N}}{2}$
- B
$N$
- ✓
$2N$
- D
$4N$
AnswerUnder similar conditions of temperature and pressure, equal volume of gas contains equal number of molecules.
$\therefore 1L = N$ molecules
$2L = 2 N$ molecules
View full question & answer→MCQ 411 Mark
Mass can neither be created nor destroyed. This is in agreement with which law of chemical combination?
- ✓
Law of definite proportion
- B
Law of multiple proportion
- C
Law of conservation of mass
- D
Law of conservation of momentum
AnswerCorrect option: A. Law of definite proportion
The Law of conservation of mass states that when elements and compounds react to form new products, mass cannot be lost or gained.
View full question & answer→MCQ 421 Mark
Which of the following terms are unitless?
AnswerMole fraction,
$\text{x}_\text{A}=\frac{\text{n}_\text{A}}{\text{n}_\text{A}+\text{n}_\text{B}}=\frac{\text{Mole of component}}{\text{Total number of moles}}\text{(unitless)}$
Mass percentage $\frac{\text{Mass of component}}{\text{Total mass}}\times100\text{(unitless)}$
View full question & answer→MCQ 431 Mark
A hydrocarbon was found to contain $75\%$ by mass of carbon and $25\%$ by mass of hydrogen. What is empirical formula of the compound?
- A
$\ce{C_2H_4}$
- B
$\ce{C_2H_6}$
- ✓
$\ce{CH_4}$
- D
$\ce{C_6H_6}$
AnswerCorrect option: C. $\ce{CH_4}$
$\frac{75}{12}:\frac{25}{1}$
$\Rightarrow6.25:25$
$\Rightarrow1:4$
View full question & answer→MCQ 441 Mark
Who is called father of modern chemistry ?
AnswerAntoine Lavoisier is known as the father of modern chemistry.
View full question & answer→MCQ 451 Mark
How many grams of concentrated nitric acid solution should be used to prepare $250\ mL$ of $\ce{2.0M HNO_3}?$ The concentrated acid is $70\%\ \ce{HNO_3}$.
- ✓
$45.0g$ conc. $\ce{HNO_3}$
- B
$90.0g$ conc. $\ce{HNO_3}$
- C
$70.0g$ conc. $\ce{HNO_3}$
- D
$54.0g$ conc. $\ce{HNO_3}$
AnswerCorrect option: A. $45.0g$ conc. $\ce{HNO_3}$
$\because$ Molarity
$=\frac{\text{Weight of HNO}_3}{\text{Molecular mass of HNO}_3\times\text{Volume of solution (in L)}}$
$\therefore$ Weight of $\ce{HNO_3}$
$=$ Molarity $\times$ Molecular mass Volume $($in $L)$
$= 2 \times 63\times\frac{1}{4} = 31.5\text{g}$
It is the weight of $100\%\ \ce{HNO_3}$
But the given acid is $70\%\ \ce{HNO_3}$
$\therefore$ Its weight $= 31.5\times\frac{100}{70}\text{g} = 45\text{g}.$
View full question & answer→MCQ 461 Mark
The laws of chemical combination formed on the basis of :
AnswerBefore Dalton, the concept of the atom was not concrete. Dalton explained atoms based on the laws of chemical combinations. When substances react, they do so by following certain laws. These laws are called the laws of chemical combination. These laws formed the basis of Dalton's atomic theory.
View full question & answer→MCQ 471 Mark
What is the atomic mass $(u)$ of chlorine?
AnswerCorrect option: B. $35.5$
Chlorine is a chemical element with the symbol $\ce{Cl}$ and atomic number $17$. The second $-$ lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them.
View full question & answer→MCQ 481 Mark
$X g$ of $\ce{Ag}$ was dissolved in $\ce{HNO_3}$ and the solution was treated with excess of $\ce{NaCl},$ when $2.87g$ of $\ce{AgCl}$ was precipitated. The value of $x$ is :
- A
$1.08g.$
- ✓
$2.16g.$
- C
$2.70g.$
- D
$1.62g.$
AnswerCorrect option: B. $2.16g.$
View full question & answer→MCQ 491 Mark
Which of the following is the best example to demonstrate the law of conservation of mass?
AnswerCorrect option: A. $12gm$ of carbon combines with $32gm$ of oxygen to form $44gm$ of $\ce{CO}^2$.
According to the law of conservation of mass :
The total mass of the reactant $=$ the total mass of the product.
Mass of reactants $= 12 + 32 = 44$ i.e $w(C) + w($oxygen$)$
Mass of products $= 44$ i.e. $w($carbon dioxide$)$
View full question & answer→MCQ 501 Mark
A compound contains $69.5\%$ oxygen, $30.5\%$ nitrogen and its molecular weight is $92$. The formula of compound is :
- A
$\ce{N_2O}$
- B
$\ce{NO_2}$
- ✓
$\ce{N_2O_4}$
- D
$\ce{N_2O_5}$
AnswerCorrect option: C. $\ce{N_2O_4}$
| Element |
$\%$ |
$\%$ at. wt |
Ratio |
| $N$ |
$30.5$ |
$\frac{30.5}{14}=2.18$ |
$1$ |
| $O$ |
$69.5$ |
$\frac{69.5}{16}=4.34$ |
$2$ |
Empirical formula $= \ce{NO_2}$
Empirical formula weight $= 46$
$\text{n} = \frac{92}{46} = 2$
$\Rightarrow $ Molecular formula $= \ce{(NO_2)_2 = N_2O_4}$ View full question & answer→