Chemistry Mcqs – (Science) MCQs Latest For FPSC, PPSC, NTS, KPPSC, SPSC & Other Tests
“ Chemistry Mcqs “. Tab this page to check “Latest Chemistry MCQs” for the preparation of competitive mcqs, FPSC mcqs, PPSC mcqs, SPSC mcqs, KPPSC mcqs, AJKPSC mcqs, BPSC mcqs, NTS mcqs, PTS mcqs, OTS mcqs, Atomic Energy mcqs, Pak Army mcqs, Pak Navy mcqs, CTS mcqs, ETEA mcqs and others. The most occurred mcqs of Chemistry in past papers. Past papers of Chemistry mcqs. Past papers of Chemistry MCQs. Chemistry Mcqs are the necessary part of any competitive / job related exams. The Chemistry mcqs having specific numbers in any written test. It is therefore everyone have to learn / remember the related Chemistry mcqs. The Important series of Chemistry Mcqs are given below:
on sp3 hybridization ________________?
A. one p-orbital is involved
B. One s and 3 p-orbitals are involved
C. All p-orbitals are involved
D. four p-orbitals are involved
What is the relative rate of effusion of CO and CO2 ?
A. CO is 1.25 times faster than CO2
B. CO is 1.25 times faster than CO
C. CO is 3.75 times faster than CO2
D. Both diffuse at the same rate
Which of the following is not considered as an intermolecular force between molecules ?
A. Coordinate covalent bonds
B. Debye forces
C. Hydrogen bonds
D. London dispersion forces
Ideal gasses have all the following characteristics except ?
A. Collisions among the molecules of an ideal gas are perfectly elastic
B. Absence of intermolecular forces
C. The molecules occupy no space
D. All of the above are correct
Under what conditions the gases deviate from the ideal behavior ?
A. Low temperature
B. High temperature
C. High pressure
D. B and C
Which one has the lowest density at room temperature ?
A. N2
B. Ne
C. NH3
D. CO
The introduction of Kelvin scale in thermodynamic is according to_______________?
A. Daltons law
B. Charles law
C. Boyles law
D. Grahams law
At constant temperature the pressure of an ideal gas is doubled its density becomes_______________?
A. Same
B. Double
C. Half
D. None
The diffusion of gases at absolute zero will be________________?
A. Slightly decreased
B. Unchanged
C. Slightly increased
D. Zero
Critical temperature for different gases is different and depends upon______________?
A. Shape of molecule
B. Size of molecule
C. Intermolecular attractions
D. All of the above
What is the simplest form of matter ?
A. Gas
B. Solid
C. Liquid
D. Semi solid
Which state of matter has the lowest density ?
A. Gas
B. Solid
C. Liquid
D. Plasma
The solid particles only posses_____________________?
A. Rotational motion
B. Vibrational motion
C. Translational motion
D. All of above motions
If 1/V is plotted on X-axis and pressure on Y-axis at constant temperature what should appear ________________?
A. Straight line parallel to x-axis
B. Curve
C. Straight line
D. Straight line parallel to y-axis
One mole of an ideal gas at 546.5 K under 2 atm pressure has a volume of________________?
A. 44.828 dm3
B. 22.414 m3
C. 22.414 dm3
D. 11.212 cm3
Which one is not the partial pressure of oxygen in the lungs ?
A. 116 torr
B. 116 mm of Hg
C. 0.1526 atm
D. 1 atm
The kinetic molecular theory of gases was put forward in 1738 by _____________________?
A. Maxell
B. Boltzman
C. Clausius
D. Bernoulli
Hydrogen effuses four times more rapidly than volume of an unknown gas molar mass of unknown gas should be_______________?
A. 48 gmol-1
B. 32 gmol-1
C. 16 gmol-1
D. 64 gmol-1
Chemistry Mcqs
The processes of effusion and diffusion are best understand by________________?
A. Avogadros law
B. Daltons law
C. Grahams law
D. Charles law
The non-ideal behaviour results chiefly from________________?
A. Elastic collisions and finite volume
B. Intermolecular attraction and infinite volume
C. Intermolecular attractions and finite volume
D. Intermolecular attraction only
Linds method is employed for__________________?
A. Expansion of gases
B. Separation of gases
C. Compression of gases
D. Liquefaction of gases
Which of these gases diffuse more quickly than oxygen ?
A. Cl2
B. NO
C. H2S
D. N2O
The weakest (in strength) of the following intermolecular forces is_______________?
A. Ionic bond
B. Vander Waals force
C. Forces among the polar molecules
D. Hydrogen bonding
Which of the following statements is true about plasma________________?
A. It is not a phase transition
B. It may be the first state of matter
C. It is a conductor of electricity
D. All of the above
0.5 mole of nitrogen gas and 0.5 mole of carbon monoxide gas at STP have same_____________?
A. Mass
B. Value of a
C. Atoms
D. Both B and C
Which of the following option is incorrect about gases ?
A. All molecules move with same speed
B. PV / RT = n
C. All molecules behave independently
D. All gases cannot be liquefied through Linds Method
In how many forms do matter exists ?
A. Five
B. Four
C. Three
D. Two
What is the abundant form of matter on earth ?
A. Liquid
B. Gas
C. Solid
D. Plasma
For a gas where volume and pressures are 1dm3 and 2 atm respectively what should be its new volume when pressure is increased to 6 atm at constant temperature ?
A. 1/4dm3
B. 1/3dm3
C. 1/2dm3
D. 2/3dm3
Which one is the right value for R ?
A. 0.0821 atm dm3k-1mol-
B. 2 cal k-1 mol-1
C. 0.0821 atm m3k-1mol-1
D. 8.314 Nm2k-1mol-1
The partial pressure exerted by the water vapours is called_______________?
A. Vapour pressure
B. Aqueous tension
C. Surface tension
D. Hydraulic pressure
The spreading of fragrance or scent in air is due to_______________?
A. Diffusion
B. Attraction with air
C. Effusion
D. Low dsensity
The highest temperature at which a substance can exist as a liquid is called its______________?
A. Critical temperature
B. Absolute temperature
C. Standard temperature
D. Upper consulate temperature
What do we call to sudden expansion of plasma ?
A. Grahams law of diffusion
B. Avogadros law
C. Joule Thompson effect
D. Daltons law of partial pressure
What will be the pressure of 1 mole of an ideal gas maintained at 300 K and 250cm3 volume ?
A. 98.5 atm
B. 95.8 atm
C. 96.7 atm
D. 97.1 atm
Who made volume and pressure correction to explain deviation of gases from ideal behaviour ?
A. Boltzman
B. Clausius
C. Charles
D. Vander waal
The gases become non-ideal at ________________?
A. Low temperature and low pressure
B. High temperature and high pressure
C. High temperature and low pressure
D. Low temperature and high pressure
The pH of 10-3 mol dm-3 of an aqueous solution of H2SO4 is_________________?
A. 2
B. 2.7
C. 3
D. 1.5
If a buffer solution of higher pH than seven is to be made we use___________________?
A. Weak acid and strong base
B. Strong acid and strong base
C. Weak acid and strong base
D. Weak acid and its salt with strong base
AgCl dissolved with conc (2×10-2) Ksp will be__________________?
A. 3.6 x 10-5
B. 3.6 x 10-6
C. 7.2 x 10-6
D. 4 x 10-4
Which of the following will not change the concentration of ammonia at the equilibrium ?
A. Increase of volume
B. Increase of pressure
C. Addition of catalyst
D. Decrease of temperature
For a reaction involving only gases at 25?C the equilibrium constant can be expressed in terms of molarity Ke or partial pressure Kp. Which is true about the numerical value of Kp ?
A. Kc is generally less than Kp
B. Kc is generally greaer than Kp
C. Kc is generally equal to Kp
D. Kc is equal to Kp if the total moles of reactants and products are equal
Which one of the following aqueous solutions will be basic ?
A. Na2SO4
B. NaCI
C. Na2CO3
D. FeCl3
Reaction which proceeds in both directions is called_______________?
A. reversible
B. spontaneous
C. irreversible
D. non-spontaneous
Conversion of reactant into product in unit time is called________________?
A. rate of forward reaction
B. rate constant
C. rate of backward reaction
D. rate co-efficient
Unit of Kc is_______________?
A. moles-2dm+6
B. moles2dm+6
C. moles+2dm-6
D. Kc may or may not have units
Rate expression for ammonia synthesis is___________________?
A. Kc=x2/v(a-x)
B. Kc=x2/(a-x)(b-x)
C. Kc=4×2/(a-2x)2(b-x)
D. Kc=4x2v2/(a-x)(b-3x)3
Catalyst used to speed up the reaction of ammonia synthesis is________________________?
A. Fe
B. V2O5 and Pt
C. V2O5
D. Pieces of Fe crystals are embedded in fused mixture of MgO Al2O3 and SiO2
By the addition of base in waterpH will be_______________?
A. more than 7
B. equal to 7
C. less than 7
D. no effect
Negative log of mular concentration of H+ ions is called___________________?
A. pH
B. pKa
C. pOH
D. pKw
Any substance which accepts H+ is base favours the concept___________________?
A. Lowrys
B. Arrhenius
C. Lewis
D. None of these
When sparingly soluble salt is in equilibrium with molar concentration of its oppositely charged ion when the product is called_________________?
A. dissociation constant
B. solubility product
C. common ion effect
D. dissociation constant for an acid
Addition of CH3COOH and CH3COONa gives in water_______________?
A. buffer solution
B. Standard solution
C. acidic buffer solution
D. both B & C
Solubility of any salt can be determined from_______________?
A. Kb
B. Ka
C. Kc
D. Ksp
By decreasing the pressure the reaction will go to that direction where_________________?
A. heat absorbed
B. volume increased
C. volume is decreased
D. no. of moles of specie decreased
Equilibrium state is achieved quickly by the addition of ________________?
A. reactants
B. base
C. acid
D. catalyst
Which one of the following is a buffer solution ?
A. glue
B. blood
C. brine
D. solution of CuSO4
Solution having the property of a very little change in pH on adding a small amount of strong acid or base is called________________?
A. buffer solution
B. standard solution
C. normal solution
D. neutral solution
Conjugated base of a weak acid is_________________?
A. moderately weak
B. strong
C. weak
D. unstable
Kc value has_______________?
A. Units
B. No units
C. Both A & B
D. None
Sodium benzoate and benzoic acid are mixed in equimolar ration to form buffer if pKa is 2 what will be the pH ?
A. 1
B. 0
C. 2
D. any one
In which of the following equilibria will Kc and Kp have the same value ?
A. N2 + 3H2 = 2NH
B. PCI5 = PCI3 + Cl2
C. 2CO + O2 = CO2
D. N2 + O2 = 2NO
Which of following is not a base______________?
A. NH3
B. KOH
C. PH3
D. BF3
Which set of solutes will form a buffer when dissolved in water to make 1 litter of solution ?
A. 0.2 mole of NaCI with 0.2 mole of HNO3
B. 0.0002M HCI
C. 0.4 mole of CH3COOH with 0.4 mole of NaOH
D. 0.4 mole of NH3 with 0.2 mole of HCI
Chemical equilibrium state is_______________?
A. dynamic state
B. free state
C. static state
D. unidirectional state
At start of reaction the concentration of reactants is_______________?
A. high
B. according to Kc
C. low
D. constant
In case of gases Kc is replaced by_______________?
A. Kb
B. Ka
C. Kp
D. K
When the value of Kc is very small then_______________________?
A. reactant conc. Is minimum
B. product conc. Is maximum
C. reaction is at start
D. reaction is completed
Idea of pH and pOH was put forward by________________?
A. Einstein
B. Gibbs
C. Sorenson
D. Chadwick
Ka<10-3 means______________?
A. Very strong acid
B. Very weak acid
C. Very strong base
D. Very strong salt
Which of the following is a macro nutrient ?
A. iron
B. boron
C. copper
D. carbon
Three elements needed for the healthy growth of plants are_________________?
A. N P K
B. N S P
C. N K C
D. N Ca P
Residence time of methane in the atmosphere is___________________?
A. 2 -3 days
B. 3 – 7 days
C. 3 – 7 years
D. 2 – 3 years
Hypochlorous acid is used for disinfecting the water it reacts with the dissolved ammonia producing___________________?
A. NHCI2
B. NH2Cl
C. NCI2
D. all of the above
Acid present in acid rain may be__________________?
A. HNO3
B. H2SO4
C. both A and B
D. none
Which of the following is not a condition for the formation of smog ?
A. sunlight
B. sufficient NO
C. less movement of air
D. winds
In which of the following layer of atmosphere there is more thickness of ozone layer ?
A. mesosphere
B. stratosphere
C. troposphere
D. photosphere
Which of the following air pollutants is more dangerous for ozone layer ?
A. CFC
B. CO
C. CO2
D. Oxides of nitrogen
Which statement is wrong ?
A. the amount of ozone layer is greater in the region close to the equator
B. in the equatorial region it acts as pollutant
C. ozone acts as filter for UV radiations
D. CFCs play effective role in removing O3 in the stratosphere
In the purification of portable water the coagulant used is_________________?
A. alum
B. copper sulphate
C. nickel sulphate
D. barium sulphate
Newspaper can be recycled again and again how many times ?
A. 3
B. 2
C. 4
D. 5
The main pollutant of leather tanneries in the waste water is____________________?
A. chromium V
B. chromium IV
C. chromium III
D. chromium VI
Which substance can be used for disinfecting water ?
A. KMnO4
B. Ozone
C. Alums
D. All
Which one of the following makes the bulk of hydrospheres content ?
A. oceans
B. fresh water lakes and ponds
C. glaciers & icecaps
D. All have equal distribution
The percentage of suspended solid waste in raw water is removed by coagulation is__________________?
A. 70
B. 60
C. 80
D. 90
The main product of bacterial action is_________________?
A. NO2
B. Nox
C. N2O3
D. NO
Pollutants have adverse effect over_________________?
A. Hydrosphere
B. Ecosystem
C. Both a & b
D. Biosphere
Which of the following is not a heavy industry ?
A. fertilizer
B. iron
C. paper
D. none
Requirement of macronutrient per acre of the land is_________________?
A. 5 to 200 kg
B. 200-400 kg
C. 20-200 kg
D. 30-400 kg
Which of the following is not a secondary pollutant_________________?
A. carbonic acid
B. ozone
C. sulphuric acid
D. carbon dioxide
Major cause of SO2 on global scale is__________________?
A. volcanoes
B. combustion
C. electric sparks
D. all
The yellow colour in photochemical smog is due to presence of__________________?
A. chlorine gas
B. nitrogen dioxide
C. dinitrogen oxide
D. chlorine dioxide
Which of the following is not primary pollutant__________________?
A. CO
B. SO3
C. NO
D. H2SO4
Which of the following gases is the main cause of acid rain ?
A. NO2
B. CO
C. both a & b
D. none of the above
Which of the following factors help to measure quallity of water ?
A. BOD
B. DO
C. COD
D. all of the above
A single chlorine free radical can destroy how many ozone molecules ?
A. 100
B. 10
C. 10000
D. 100000
Chlorination of water may be harmful if the water contains_________________?
A. Ammonia
B. Carbon dixide
C. Dissolved oxygen
D. All
Which of the following is used as water disinfectant to avoid the formation of toxic compounds_________________?
A. O3
B. Cl2
C. ClO2
D. both B & C
Ozone hole is substantial depletion of ozone in every year during__________________?
A. Nov – Dec
B. Sep – Nov
C. Aug – Nov
D. Dec – Jan
Which of the following solutions of H2SO4 is more concentrated ?
A. 1 Molar solution
B. 1 normal solution
C. 1 molal solution
D. all have same concentration