CBSE Questions for Class 11 Medical Chemistry Some Basic Concepts Of Chemistry Quiz 8 - MCQExams.com

Calculate the total number of oxygen atoms present in $$1.80g$$ of glucose $$({C}_{6}{H}_{12}{O}_{6})$$.
  • $$46.138\times10^{21}$$
  • $$36.138\times10^{21}$$
  • $$26.138\times10^{21}$$
  • $$6.138\times10^{21}$$
A precipitate of AgClAgCl and AgBrAgBr has the mass 0.40660.4066 g. On heating a current of chlorine, the AgBrAgBr is converted to AgClAgCl and the mixture loses 0.07250.0725 in mass. The %% of mass in the original mixture is (as the nearest integer) :
  • 2 %
  • 6 %
  • 5%
  • 95%
Carbon dating method is used to determine the age of ________.
  • Rock
  • Fossils
  • Trees
  • Ancient monuments
What mass of propene is formed from 34.0 g of iodopropane on heating with ethanolic $$KOH$$, if the yield is 36 %?
  • 17.2 g
  • 8.4 9
  • 3.024 g
  • 1.72 g
An organic compound made of $$C, H$$ and $$N$$ contains $$20$$% nitrogen. Its  minimum molecular weight is:
  • $$70$$
  • $$140$$
  • $$100$$
  • $$65$$
$$CH_3CH_2CH_2CH_{3(g)}\rightleftharpoons CH_3-\underset{iso-butane}{\underset{CH_3}{\underset{|}{C}H}}-CH_{3(g)}$$
  • $$75\%$$
  • $$90\%$$
  • $$30\%$$
  • $$60\%$$
What will be the mass percentage of a resulting solution prepared by mixing $$15\%$$ (w/w) 500 g aqueous solution of the area with $$25\%$$ (w/w) 400g aqueous solution of it?
  • $$18\%$$
  • $$20\%$$
  • $$25\%$$
  • $$15\%$$
The critical volume of a gas is 0.036 $$lit. mol^{-1}$$. The radius of the molecule will be (in cm):
(Avogadro Number = $$6 \times 10^{23}$$)
  • $$\displaystyle \left( \frac{9}{4 \pi} \times 10^{-23} \right)^{\dfrac{1}{3}}$$
  • $$\displaystyle \left( \frac{8 \pi}{3} \times 10^{-23} \right)^{\dfrac{1}{3}}$$
  • $$\displaystyle \left( \frac{3}{8 \pi} \times 10^{-23} \right)^{\dfrac{1}{3}}$$
  • none of these
A sample of oxygen contain $$_{ 8 }^{ 16 }{ O },_{ 8 }^{ 17 }{ O }$$ and $$_{ 8 }^{ 18 }{ O }$$ atoms has average atomic mass $$16.12$$. If mole $$\%$$ of $$_{ 8 }^{ 16 }{ O }$$ is $$90$$, then weight $$\%$$ of $$_{ 8 }^{ 18 }{ O }$$ is 
  • $$2$$
  • $$2.33$$
  • $$1.79$$
  • $$8$$
At $$-50^0C$$, liquid $$NH_3$$ has ionic product is $$10^{-30}$$. How many amide $$(NH_2{^-})$$ ions are present per $$mm^3$$ in pure liquid $$NH_3$$ ? Take $$N_a \, = \, 6 \times \, 10^{23}$$
  • 602
  • 567
  • 450
  • 892
What will be the mass of 100 atoms of hydrogen?
  • $$100\ g$$
  • $$1.66 \times 10^{-22}$$ g
  • $$6.023 \times 10^{23}$$ g
  • $$100 \times 6.023 \times 10^{23}$$ g
For every ,one $$^{37}Cl$$ isotope there are three $$^{35}Cl$$ isotopes, in a sample of chlorine. What will be the average atomic mass of chlorine?
  • 35
  • 37
  • 35.5
  • 35.6
At $$\displaystyle\, 80^{\circ}C$$ the vapour pressure of pure liquid A is 250 mm of Hg and that of pure liquid B is 1000 mm of Hg. If a solution of A and B boils at $$\displaystyle\, 80^{\circ}C$$ and 1 atm pressure, the amount of A in the mixture is (1 atm = 760 mm Hg) 
  • 50 mole percent
  • 52 mole percent
  • 34 mole percent
  • 48 mole percent
Which symbol is used to represent the unit of atomic mass, amu?
  • u
  • A
  • M
  • n
4.88 g of $$KClO_3$$ when heated produced 1.92 g of $$O_2$$ and 2.96 g of KCl. Which of the following statements regarding the experiment is correct?
  • The result illustrates the law of conservation of mass.
  • The result illustrates the law of multiple proportions.
  • The result illustrates the law of constant proportion.
  • None of the above laws is being illustrated here.
Which of the following statements best explains the law of conservation of mass, concerning a chemical change?
  • 100 g of water is heated to give steam.
  • A sample of $$N_2$$ gas is heated at constant pressure without any change in mass.
  • 36 g of carbon combines with 32 g of oxygen to form 68 g of $$CO_2$$.
  • 10 g of carbon is heated in vacuum without any change in mass.
Oxygen occurs in nature as a mixture of isotopes $$^16O$$, $$^17O$$ and $$^18O$$ having atomic masses of 15.995 u, 16.999 u and 17.999 u and relative abundance of 99.763%, 0.037%, and 0.200% respectively. What is the average atomic mass of oxygen?
  • 15.999 u
  • 16.999 u
  • 17.999 u
  • 18.999 u
The density of a gas is $$1.78 \ g \ L^{-1}$$ at STP. The weight of one mole of gas is:
  • $$39.9\ g$$
  • $$22.4\ g$$
  • $$3.56\ g$$
  • $$29\ g$$
Which of the following gases will have least volume if 10 g of each gas is taken at same temperature and pressure?
  • $$CO_2$$
  • $$N_2$$
  • $$CH_4$$
  • $$HCl$$
Total number of atoms present in 34 g of $$NH_3$$ is:
  • $$4 \times 10^{23}$$
  • $$4.8 \times 10^{21}$$
  • $$2 \times 10^{23}$$
  • $$48 \times 10^{23}$$
A solution is prepared by adding $$5\ g$$ of a solute $$'X'$$ to $$45\ g$$ of solvent $$'Y'$$. What is the mass percent of solute $$'X'$$?
  • $$10\%$$
  • $$11.1\%$$
  • $$90\%$$
  • $$75\%$$
The correct match is 
1528901_227219042fb042b7ba7f3c4bbfb8ee16.jpg
  • $$a = p \quad b = r \quad c = q \quad d = s$$
  • $$a = r \quad b = q \quad c = s \quad d = p$$
  • $$a = r \quad b = q \quad c = p \quad d = s$$
  • $$a = r \quad b = p \quad c = s \quad d = q$$
How much mass of sodium acetate is required to make 250 mL of 0.575 molar aqueous solution? 
  • $$11.79 g$$
  • $$15.38 g$$
  • $$10.81 g$$
  • $$25.35 g$$
An impure sample of silver $$(1.5\ g)$$ is heated with $$S$$ to form $$0.124\ g$$ of $$Ag_2S$$. What was the per cent yield of $$Ag_2S$$?
  • $$21.6\%$$
  • $$7.2\%$$
  • $$1.7\%$$
  • $$24.8\%$$
How many number of aluminium ions are present in 0.051 g of aluminium oxide? 
  • $$6.023 \times 10^{20}$$ ions
  • $$3$$ ions
  • $$6.023 \times 10^{23}$$ ions
  • $$9$$ ions
Which scientist discovered that the same amount of space was occupied by equal numbers of molecules of gases, irrespective of whether it was hydrogen or chlorine or fluorine?
  • Gay-Lussac
  • Avogadro
  • Marconi
  • Wohler
What will be the weight of CO having the same number of oxygen atoms as present in 22 g of $$CO_2$$?
  • 28 g
  • 22 g
  • 44 g
  • 72 g
Which of the following statement about Avogadro's hypothesis is correct?
  • At NTP all gases contain same number of molecules
  • Under similar conditions of temperature and pressure, gases react with each other in simple ratio.
  • Under similar conditions of temperature and pressure, equal volumes of all gases contain same number of molecules
  • Gases always react with gases only at the given temperature and pressure
Read the passage given below and answer the question:
Chemical reactions involve the interaction of atoms and molecules. A large number of atoms/molecules (approximately $$6.023 \times 10^{23}$$) are present in few grams of any chemical compound varying with their atomic/molecular masses. To handle such large numbers conveniently, the mole concept was introduced. This concept has implications in diverse areas such as analytical chemistry,  biochemistry, electrochemistry, and radiochemistry. the following example illustrates a typical case, involving chemical/electrochemical reaction, which requires a clear understanding of the mole concept.
A 4.0 molar aqueous solution of NaCl is prepared and 500 mL of this solution is electrolyzed. This leads to the evolution of chlorine gas at one of the electrodes (atomic mass: Na = 23, Hg = 200; 1 faraday =96500 coulombs). 
If the cathode is a Hg electrode, the maximum weight (g) of amalgam formed from this solution is:
  • 200
  • 225
  • 400
  • 446
Major problems faced by energy section are
  • Rising oil prices
  • Rising oil import bill
  • Sick SEBs
  • All of the above
How many grams $$NaOH$$ are present in $$250\ mL$$ of $$0.5\ M$$ $$NaOH$$ solution?
  • $$7.32g$$
  • $$3.8g$$
  • $$5g$$
  • $$0.5g$$
According to Avogadro's hypothesis, equal volumes of gases under the same conditions of temperature and pressure will contain:
  • the same number of molecules
  • different number of molecules
  • the same number of molecules only if their molecular masses are equal
  • the same number of molecules if their densities are equal.
'Equal volumes of all gases at the same temperature and pressure contain equal number of molecules'. This law is called as
  • Boyle's law
  • Charle's law
  • Avogadro's law
  • Gay Lussac's law
Thermal electricity is generated from:
  • oil
  • coal
  • gas
  • all of the above
A sample of calcium carbonate $$(CaCO_{3})$$ has the following percentage composition: $$Ca = 40\%; \ C = 12\%; \ O = 48\%$$.
If the law of constant proportions is true, then the weight of calcium in $$4 g$$ of a sample of calcium carbonate from another source will be:
  • $$0.016\ g$$
  • $$0.16\ g$$
  • $$1.6\ g$$
  • $$16\ g$$
0.46 g of an organic compound  was analysed. The increase in mass of $$ CaCl_2$$ U-Tube  was 0.54 g and potash bulb was 0.88 g. The percentage composition  of the compound is:
  • C=52.17%, H=13.04%, O=34.79%
  • C=50%,H=50%
  • C=32.19%,H= 18.01%,O=49.8%
  • C=72%,H=28%
One gm metal $$M^{3+}$$ was discharged by the passage of $$1.81\times 10^{23}$$ electrons. What is the atomic mass of metal?
  • $$8g/mol$$
  • $$9g/mol$$
  • $$10g/mol$$
  • None of these
The number of atoms in 67.2 L of $${ NH }_{ 3 }$$(g) at STP is:
  • 9 $${N }_{ A }$$
  • 12 $${N }_{ A }$$
  • 3 $${N }_{ A }$$
  • 4 $${N }_{ A }$$
The density (in g $$ml^{-1}$$) of a $$3.60$$M sulphuric acid solution having $$29\%$$ $$H_2SO_4$$ [molar mass $$=98$$g $$mol^{-1}$$] by mass, will be:
  • $$1.64$$
  • $$1.88$$
  • $$1.22$$
  • $$1.45$$
A sample of municipal water contains one part of urea (molecular wt $$=60$$) per million parts of water by weight. The number of urea molecules in a drop of water of volume $$0.05\ ml$$ is 
  • $$2.5\times 10^{14}$$
  • $$5\times 10^{14}$$
  • $$5\times 10^{13}$$
  • $$5\times 10^{15}$$
A $$10.0g$$ a sample of a mixture of calcium chloride and sodium chloride is treated with $$Na_2CO_3$$ to precipitate the calcium as calcium carbonate. This $$CaCO_3$$ is heated to convert all the calcium to $$CaO$$ and the final mass of $$CaO$$ is $$1.62gms$$. The $$\%$$ by mass of $$CaCl_2$$ in the original mixture is :
  • $$15.2\%$$
  • $$32.1\%$$
  • $$21.8\%$$
  • $$11.07\%$$
If you are given Avogadro's number of atoms of a gas $$X$$. If half of the atoms are converted into $$X_{(g)}^+$$ by energy $$\Delta H$$. The IE of $$X$$ is :
  • $$\dfrac{2\Delta H}{N_A}$$
  • $$\dfrac{2N_A}{\Delta H}$$
  • $$\dfrac{\Delta H}{2N_A}$$
  • $$\dfrac{N_A}{\Delta H}$$
The mass of a molecule of the compound $$C_{60}H_{122}$$ is __________.
  • $$1.4\times 10^{-21}$$ g
  • $$1.09\times 10^{-21}$$ g
  • $$5.025\times 10^{23}$$ g
  • $$16.023\times 10^{23}$$ g
The total number of electrons in 4.2 g of $$N^{3-}$$ ion is: ($$N_A$$ is the Avogadro's number )
  • $$2.1 N_A$$
  • $$4.2 N_A$$
  • $$3 N_A$$
  • $$3.2 N_A$$
The percentage of pyridine $$(C_5H_5N)$$ that forms pyridinium ion $$(C_5H_5NH)$$ in a $$0.10$$M aqueous pyridine solution is:
[$$K_b$$ for $$C_5H_5N=1.7\times 10^{-9}$$]
  • $$0.77\%$$
  • $$1.6\%$$
  • $$0.0060\%$$
  • $$0.013\%$$
The amount of zinc required to produce $$224$$ ml of $$H_2$$ at NTP on treatment with dilute $$H_2SO_4$$ solution will be:
  • $$0.65$$g
  • $$0.065$$ g
  • $$65$$g
  • $$6.5$$g
What quantity of lime stone on heating will give $$56\ kg$$ of $$CaO$$?
  • $$1000\ kg$$
  • $$56\ kg$$
  • $$44\ kg$$
  • $$100\ kg$$
What mass of sodium chloride will react with 34.0 g of silver nitrate to produce 17 g of sodium nitrate and 28.70 g of silver chloride if the law of conservation of mass holds good ?
  • 12.35 grams
  • 11.70 grams
  • 9.32 grams
  • None of these
If average molecular wt. of air is 29, then assuming $$N_2$$ and $$O_2$$ gases are there which options are correct regarding composition of air:
i) 75% by mass of $$N_2$$
ii) 75% by moles $$N_2$$
iii) 72.41% by mass of $$N_2$$
  • only (i) is correct
  • only (ii) is correct
  • both (ii) and (iii) are correct
  • both (i) and (ii) are correct
$$4.6$$ $$cm^3$$ of methyl alcohol is dissolved in $$25.2$$g of water with density $$0.8$$. Calculate $$\%$$ by mass of methyl alcohol.
  • $$14.72$$
  • $$10.67$$
  • $$12.74$$
  • $$13.45$$
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