Join WhatsApp ChannelDaily MCQs & Exam Updates

CSS MCQs

Civil Superior Services β€” Complete MCQ Bank

899 Questions
Exam Preparation Guide

How to prepare for CSS

CSS is Pakistan’s premier federal competitive examination. Strong preparation requires conceptual clarity, broad general knowledge and consistent practice across compulsory and optional areas.

Pakistan AffairsCurrent AffairsEnglishEveryday Science
Combine daily MCQ practice with analytical reading, vocabulary building and regular revision of national and international affairs.
CSS preparation illustration
61
Biology Medium

What is the term for the physical appearance or observable characteristics of an organism?

  • AGenome
  • BGenotype
  • CKaryotype
  • DPhenotype
Permalink
Correct Answer: Option D β€” Phenotype
Explanation: Phenotype refers to the observable physical and biochemical characteristics of an organism resulting from the interaction of its genotype with the environment.
Submitted by: PaperMCQs
62
Chemistry Medium

Which type of chemical bond involves atoms sharing electrons unequally due to difference in electronegativity?

  • ANon-polar covalent bond
  • BPolar covalent bond
  • CMetallic bond
  • DIonic bond
Permalink
Correct Answer: Option B β€” Polar covalent bond
Explanation: A polar covalent bond forms when electrons are shared unequally between atoms of different electronegativities creating partial positive and negative charges on the molecule as in water.
Submitted by: PaperMCQs
63
Chemistry Medium

Which type of formula shows all the bonds between atoms in a molecule?

  • AEmpirical formula
  • BStructural formula
  • CMolecular formula
  • DIonic formula
Permalink
Correct Answer: Option B β€” Structural formula
Explanation: A structural formula shows all the atoms in a molecule and the bonds between them either as a displayed formula showing each bond or as a condensed structural formula.
Submitted by: PaperMCQs
64
Chemistry Medium

Which indicator is colourless in acidic solution and pink in alkaline solution?

  • ALitmus
  • BMethyl orange
  • CUniversal indicator
  • DPhenolphthalein
Permalink
Correct Answer: Option D β€” Phenolphthalein
Explanation: Phenolphthalein is colourless in acidic and neutral solutions but turns pink to magenta in alkaline solutions and is commonly used as an indicator in acid-base titrations.
Submitted by: PaperMCQs
65
Chemistry Hard

Which law states that the amount of substance deposited during electrolysis is directly proportional to the quantity of electricity passed?

  • ABoyle's Law
  • BGay-Lussac's Law
  • CAvogadro's Law
  • DFaraday's First Law of Electrolysis
Permalink
Correct Answer: Option D β€” Faraday's First Law of Electrolysis
Explanation: Faraday's First Law of Electrolysis states that the mass of a substance deposited at an electrode during electrolysis is directly proportional to the quantity of charge passed.
Submitted by: PaperMCQs
66
Chemistry Hard

What is the chemical formula for chloroform a once common anaesthetic?

  • ACH2Cl2
  • BCCl4
  • CCHCl2
  • DCHCl3
Permalink
Correct Answer: Option D β€” CHCl3
Explanation: Chloroform has the chemical formula CHCl3 and was historically used as an anaesthetic and is now used as a solvent in chemical synthesis and laboratory work.
Submitted by: PaperMCQs
67
Chemistry Medium

Which type of reaction in organic chemistry involves replacing a hydrogen atom with another atom or group?

  • AElimination
  • BSubstitution
  • CAddition
  • DHydrolysis
Permalink
Correct Answer: Option B β€” Substitution
Explanation: Substitution reactions replace one atom or group in a molecule with another as seen when chlorine substitutes hydrogen in methane under UV light producing chloromethane.
Submitted by: PaperMCQs
68
Chemistry Medium

What is the formula for calculating moles from mass and molar mass?

  • AMoles equals mass times molar mass
  • BMoles equals molar mass divided by mass
  • CMoles equals mass divided by molar mass
  • DMoles equals mass times volume
Permalink
Correct Answer: Option C β€” Moles equals mass divided by molar mass
Explanation: Moles are calculated by dividing the mass of a substance in grams by its molar mass in grams per mole providing the fundamental calculation in all stoichiometry problems.
Submitted by: PaperMCQs
69
Chemistry Medium

Which process is used to separate crude oil into useful fractions based on different boiling points?

  • AFractional distillation
  • BChromatography
  • CCrystallisation
  • DFiltration
Permalink
Correct Answer: Option A β€” Fractional distillation
Explanation: Fractional distillation separates crude oil into fractions with different boiling points in a fractionating column producing petrol kerosene diesel lubricating oil and bitumen.
Submitted by: PaperMCQs
70
Chemistry Medium

Which element is liquid at room temperature and is the only non-metal element in this state?

  • AMercury
  • BBromine
  • CGallium
  • DCaesium
Permalink
Correct Answer: Option B β€” Bromine
Explanation: Bromine is the only non-metal element that exists as a liquid at room temperature appearing as a reddish-brown volatile liquid with a pungent irritating smell.
Submitted by: PaperMCQs