questions.json

[
  {
      "id": 1,
      "question": "What does a material balance primarily apply?",
      "options": ["Conservation of energy", "Conservation of mass", "Conservation of momentum", "Conservation of volume"],
      "answer": "Conservation of mass"
    },
    {
      "id": 2,
      "question": "In chemical engineering, a system is defined as:",
      "options": ["The entire universe", "A specified portion of matter under study", "Only open processes", "Any equipment used"],
      "answer": "A specified portion of matter under study"
    },
    {
      "id": 3,
      "question": "The imaginary surface that separates a system from its surroundings is called:",
      "options": ["Control volume", "Boundary", "Interface", "Surface tension"],
      "answer": "Boundary"
    },
    {
      "id": 4,
      "question": "Which law is the basis of material balances?",
      "options": ["Law of conservation of energy", "Law of conservation of entropy", "Law of conservation of mass", "Law of definite proportions"],
      "answer": "Law of conservation of mass"
    },
    {
      "id": 5,
      "question": "Which type of process has no mass entering or leaving during operation?",
      "options": ["Batch process", "Continuous process", "Semi-batch process", "Cyclic process"],
      "answer": "Batch process"
    },
    {
      "id": 6,
      "question": "In a continuous process, the system operates:",
      "options": ["With intermittent input", "With constant inflow and outflow", "With no inflow", "Only in cycles"],
      "answer": "With constant inflow and outflow"
    },
    {
      "id": 7,
      "question": "A semi-batch process is best described as:",
      "options": ["No inflow or outflow", "Continuous inflow and outflow", "Either inflow or outflow but not both", "No chemical reaction"],
      "answer": "Either inflow or outflow but not both"
    },
    {
      "id": 8,
      "question": "The surroundings of a system include:",
      "options": ["Only air", "Everything external to the system boundary", "The same molecules in the system", "The equipment walls only"],
      "answer": "Everything external to the system boundary"
    },
    {
      "id": 9,
      "question": "Material balance can be expressed mathematically as:",
      "options": ["Input + Output = Accumulation", "Input – Output + Generation – Consumption = Accumulation", "Input × Output = Accumulation", "Input + Energy = Accumulation"],
      "answer": "Input – Output + Generation – Consumption = Accumulation"
    },
    {
      "id": 10,
      "question": "If a system is at steady state, then:",
      "options": ["Accumulation term is zero", "Input is zero", "Output is zero", "Generation is zero"],
      "answer": "Accumulation term is zero"
    },
    {
      "id": 11,
      "question": "Which of the following is a closed system?",
      "options": ["A boiling pot with lid", "A running distillation column", "A cooling tower", "An open water tank"],
      "answer": "A boiling pot with lid"
    },
    {
      "id": 12,
      "question": "An open system is also known as:",
      "options": ["Isolated system", "Control volume", "Closed vessel", "Batch system"],
      "answer": "Control volume"
    },
    {
      "id": 13,
      "question": "The law of conservation of mass implies:",
      "options": ["Matter can be destroyed", "Mass remains constant in physical and chemical changes", "Mass decreases in reactions", "Energy converts into mass"],
      "answer": "Mass remains constant in physical and chemical changes"
    },
    {
      "id": 14,
      "question": "In which process is there no mass transfer across boundaries?",
      "options": ["Open system", "Isolated system", "Continuous system", "Semi-batch process"],
      "answer": "Isolated system"
    },
    {
      "id": 15,
      "question": "Which of the following is NOT an assumption in material balances?",
      "options": ["Perfect mixing", "Constant density", "Instantaneous reaction", "No conservation of mass"],
      "answer": "No conservation of mass"
    },
    {
      "id": 16,
      "question": "In batch processes, material balances are generally performed:",
      "options": ["On a time-average basis", "Over the whole duration of the process", "At steady state only", "Only for gaseous systems"],
      "answer": "Over the whole duration of the process"
    },
    {
      "id": 17,
      "question": "In continuous processes, balances are often performed:",
      "options": ["At steady state", "During shutdown only", "Only for solids", "Only in laboratory scale"],
      "answer": "At steady state"
    },
    {
      "id": 18,
      "question": "Which type of system exchanges neither mass nor energy with surroundings?",
      "options": ["Closed system", "Open system", "Isolated system", "Semi-batch process"],
      "answer": "Isolated system"
    },
    {
      "id": 19,
      "question": "The mass balance equation reduces to Input = Output when:",
      "options": ["At steady state with no reaction", "At unsteady state", "When generation occurs", "When accumulation occurs"],
      "answer": "At steady state with no reaction"
    },
    {
      "id": 20,
      "question": "A control mass approach is generally applied to:",
      "options": ["Closed systems", "Open systems", "Continuous reactors", "Steady flow systems"],
      "answer": "Closed systems"
    },
    {
      "id": 21,
      "question": "A control volume approach is applied to:",
      "options": ["Closed systems", "Open systems", "Isolated systems", "Batch processes only"],
      "answer": "Open systems"
    },
    {
      "id": 22,
      "question": "If 100 kg of reactant is fed and 80 kg of product is obtained, what is the material lost?",
      "options": ["10 kg", "20 kg", "80 kg", "100 kg"],
      "answer": "20 kg"
    },
    {
      "id": 23,
      "question": "A balance on a semi-batch reactor considers:",
      "options": ["No inflow or outflow", "Only energy balances", "Either inflow or outflow", "Both inflow and outflow continuously"],
      "answer": "Either inflow or outflow"
    },
    {
      "id": 24,
      "question": "If accumulation is positive, it means:",
      "options": ["System mass is decreasing", "System mass is increasing", "Steady state is reached", "No reaction is occurring"],
      "answer": "System mass is increasing"
    },
    {
      "id": 25,
      "question": "If accumulation is zero, the system is said to be:",
      "options": ["At steady state", "Unsteady", "Batch operated", "Reacting"],
      "answer": "At steady state"
    },
    {
      "id": 26,
      "question": "A system where both input and output occur but accumulation is zero is:",
      "options": ["Batch", "Continuous steady state", "Semi-batch", "Isolated"],
      "answer": "Continuous steady state"
    },
    {
      "id": 27,
      "question": "Which of the following is an example of a batch process?",
      "options": ["Fermentation tank", "Petroleum refinery", "Paper manufacturing", "Power plant"],
      "answer": "Fermentation tank"
    },
    {
      "id": 28,
      "question": "Which of the following is an example of a continuous process?",
      "options": ["Cooking rice in a cooker", "Sugar production", "Distillation column in operation", "Pharmaceutical mixing"],
      "answer": "Distillation column in operation"
    },
    {
      "id": 29,
      "question": "Which of the following is an example of semi-batch process?",
      "options": ["Boiler furnace", "Chlorination of water with continuous gas supply", "Refinery distillation column", "Gas turbine"],
      "answer": "Chlorination of water with continuous gas supply"
    },
    {
      "id": 30,
      "question": "Which process type is more suitable for large-scale production?",
      "options": ["Batch", "Continuous", "Semi-batch", "Isolated"],
      "answer": "Continuous"
    },
    {
      "id": 31,
      "question": "Which process type is more flexible for small-scale production?",
      "options": ["Batch", "Continuous", "Semi-batch", "Isolated"],
      "answer": "Batch"
    },
    {
      "id": 32,
      "question": "For material balance, the general rule is:",
      "options": ["Mass in = Mass out + Accumulation", "Mass in = Mass out", "Mass in > Mass out", "Mass in < Mass out"],
      "answer": "Mass in = Mass out + Accumulation"
    },
    {
      "id": 33,
      "question": "Which of the following requires time-dependent balance?",
      "options": ["Steady state", "Unsteady state", "Isolated systems", "Continuous refinery"],
      "answer": "Unsteady state"
    },
    {
      "id": 34,
      "question": "In which type of system is boundary fixed in space?",
      "options": ["Control mass system", "Control volume system", "Isolated system", "Batch process"],
      "answer": "Control volume system"
    },
    {
      "id": 35,
      "question": "Which system has a moving boundary?",
      "options": ["Control mass system", "Control volume system", "Isolated system", "Continuous process"],
      "answer": "Control mass system"
    },
    {
      "id": 36,
      "question": "Which of the following best explains semi-batch?",
      "options": ["Time-independent", "Combination of batch and continuous", "Closed system", "Energy balance only"],
      "answer": "Combination of batch and continuous"
    },
    {
      "id": 37,
      "question": "If output > input in a balance, then accumulation is:",
      "options": ["Positive", "Negative", "Zero", "Infinite"],
      "answer": "Negative"
    },
    {
      "id": 38,
      "question": "If input = output, then accumulation is:",
      "options": ["Zero", "Positive", "Negative", "Unsteady"],
      "answer": "Zero"
    },
    {
      "id": 39,
      "question": "If a reaction generates mass, which term in the balance is positive?",
      "options": ["Generation", "Consumption", "Input", "Output"],
      "answer": "Generation"
    },
    {
      "id": 40,
      "question": "Which type of material balance is easiest to perform?",
      "options": ["Batch without reaction", "Continuous with reaction", "Semi-batch with accumulation", "Unsteady reactive system"],
      "answer": "Batch without reaction"
    },
  {
    "id": 1,
    "question": "What does the law of conservation of mass state in material balances?",
    "options": [
      "Mass can be created or destroyed depending on the process",
      "Mass can neither be created nor destroyed in a closed system",
      "Mass is always lost in chemical processes",
      "Mass depends on the type of material"
    ],
    "answer": "Mass can neither be created nor destroyed in a closed system"
  },
  {
    "id": 2,
    "question": "In a single-unit material balance, the general form is:",
    "options": [
      "Input = Output + Accumulation",
      "Input - Output = 0",
      "Input + Output = Accumulation",
      "Input = Output - Generation"
    ],
    "answer": "Input = Output + Accumulation"
  },
  {
    "id": 3,
    "question": "Which of the following is true for a steady-state process?",
    "options": [
      "Mass accumulation is not zero",
      "Mass accumulation is zero",
      "Energy accumulation is infinite",
      "Process variables change with time"
    ],
    "answer": "Mass accumulation is zero"
  },
  {
    "id": 4,
    "question": "Which of these is an example of a single-unit operation?",
    "options": [
      "A distillation column with recycle",
      "A simple mixer with two inlets and one outlet",
      "A process with recycle and purge streams",
      "A complex multi-reactor system"
    ],
    "answer": "A simple mixer with two inlets and one outlet"
  },
  {
    "id": 5,
    "question": "In multiple-unit processes, material balances are usually solved by:",
    "options": [
      "Writing separate balances for each unit",
      "Writing only an overall balance",
      "Ignoring the recycle streams",
      "Only using bypass calculations"
    ],
    "answer": "Writing separate balances for each unit"
  },
  {
    "id": 6,
    "question": "The purpose of a recycle stream is to:",
    "options": [
      "Increase raw material consumption",
      "Improve conversion and reduce waste",
      "Decrease product purity",
      "Reduce process cost always"
    ],
    "answer": "Improve conversion and reduce waste"
  },
  {
    "id": 7,
    "question": "What is a bypass stream?",
    "options": [
      "A stream that passes around part of a process unit",
      "A stream that goes through the entire process",
      "A stream that is purged to remove impurities",
      "A recycle stream from the reactor"
    ],
    "answer": "A stream that passes around part of a process unit"
  },
  {
    "id": 8,
    "question": "Why is a purge stream necessary in recycle systems?",
    "options": [
      "To increase the flow rate",
      "To remove inert or undesired materials that may accumulate",
      "To improve heat transfer efficiency",
      "To maximize energy efficiency"
    ],
    "answer": "To remove inert or undesired materials that may accumulate"
  },
  {
    "id": 9,
    "question": "Which of these represents an unsteady-state balance?",
    "options": [
      "Input = Output",
      "Input - Output = Accumulation",
      "Input = Output + 0",
      "Input + Output = Accumulation + 0"
    ],
    "answer": "Input - Output = Accumulation"
  },
  {
    "id": 10,
    "question": "At steady-state, the accumulation term in the material balance equation is:",
    "options": [
      "Zero",
      "Positive",
      "Negative",
      "Infinite"
    ],
    "answer": "Zero"
  },
  {
    "id": 11,
    "question": "Which of the following is an example of a purge requirement?",
    "options": [
      "Accumulation of inert gases in an ammonia synthesis loop",
      "Accumulation of heat in a heat exchanger",
      "Accumulation of reactants in a distillation column",
      "Accumulation of pressure in a compressor"
    ],
    "answer": "Accumulation of inert gases in an ammonia synthesis loop"
  },
  {
    "id": 12,
    "question": "In a material balance without chemical reaction, which terms are absent?",
    "options": [
      "Generation and Consumption terms",
      "Input and Output terms",
      "Accumulation terms",
      "Flow terms"
    ],
    "answer": "Generation and Consumption terms"
  },
  {
    "id": 13,
    "question": "Which of these processes is unsteady-state?",
    "options": [
      "Filling a tank",
      "Continuous distillation at constant feed",
      "Evaporation at constant rate",
      "Heat exchanger at steady operation"
    ],
    "answer": "Filling a tank"
  },
  {
    "id": 14,
    "question": "In multiple-unit balances, the best approach is:",
    "options": [
      "Solve each unit separately and then combine results",
      "Ignore intermediate units",
      "Write only one overall balance",
      "Use only trial-and-error methods"
    ],
    "answer": "Solve each unit separately and then combine results"
  },
  {
    "id": 15,
    "question": "Recycle ratio is defined as:",
    "options": [
      "Recycle flow rate / Fresh feed flow rate",
      "Fresh feed flow rate / Product flow rate",
      "Product flow rate / Recycle flow rate",
      "Recycle flow rate × Fresh feed flow rate"
    ],
    "answer": "Recycle flow rate / Fresh feed flow rate"
  },
  {
    "id": 16,
    "question": "Which of these is NOT a reason to use recycle?",
    "options": [
      "To improve conversion",
      "To save energy",
      "To remove inerts",
      "To increase raw material consumption"
    ],
    "answer": "To increase raw material consumption"
  },
  {
    "id": 17,
    "question": "If the process is at unsteady-state, what happens to accumulation?",
    "options": [
      "It remains zero",
      "It becomes non-zero",
      "It is undefined",
      "It is negative only"
    ],
    "answer": "It becomes non-zero"
  },
  {
    "id": 18,
    "question": "Which of these operations often requires a bypass?",
    "options": [
      "Heat exchanger for temperature control",
      "Mixer for uniform blending",
      "Reactor for maximum conversion",
      "Separator for purity increase"
    ],
    "answer": "Heat exchanger for temperature control"
  },
  {
    "id": 19,
    "question": "What type of balance is applied to a tank being drained without inflow?",
    "options": [
      "Steady-state balance",
      "Unsteady-state balance",
      "Overall balance",
      "Multiple-unit balance"
    ],
    "answer": "Unsteady-state balance"
  },
  {
    "id": 20,
    "question": "In a process with a recycle and purge, the purge stream prevents:",
    "options": [
      "Decrease in product flow",
      "Accumulation of inert gases",
      "Increase in recycle flow",
      "Excess energy usage"
    ],
    "answer": "Accumulation of inert gases"
  },
  {
    "id": 21,
    "question": "For a mixing process without reaction, which equation applies?",
    "options": [
      "Total input mass = Total output mass",
      "Total input mass ≠ Total output mass",
      "Total input = Generation + Output",
      "Total output = Input - Accumulation"
    ],
    "answer": "Total input mass = Total output mass"
  },
  {
    "id": 22,
    "question": "Which of these is correct about steady-state?",
    "options": [
      "Variables depend on time",
      "Mass accumulation is zero",
      "System is always closed",
      "No output exists"
    ],
    "answer": "Mass accumulation is zero"
  },
  {
    "id": 23,
    "question": "In unsteady-state balances, time factor is:",
    "options": [
      "Not important",
      "Important as variables change with time",
      "Always constant",
      "Used only in steady processes"
    ],
    "answer": "Important as variables change with time"
  },
  {
    "id": 24,
    "question": "Which of these is an example of single-unit balance?",
    "options": [
      "Evaporation of water in a single vessel",
      "Distillation with recycle",
      "Ammonia synthesis loop with purge",
      "A refinery process with multiple heaters"
    ],
    "answer": "Evaporation of water in a single vessel"
  },
  {
    "id": 25,
    "question": "The main difference between overall and individual unit balances is:",
    "options": [
      "Overall balance ignores internal flows",
      "Overall balance includes internal flows",
      "Unit balances are approximate",
      "Overall balances are less accurate"
    ],
    "answer": "Overall balance ignores internal flows"
  },
  {
    "id": 26,
    "question": "Bypass is used mainly for:",
    "options": [
      "Controlling process conditions",
      "Increasing reaction conversion",
      "Improving separation efficiency",
      "Reducing product purity"
    ],
    "answer": "Controlling process conditions"
  },
  {
    "id": 27,
    "question": "In unsteady-state operation, accumulation can be:",
    "options": [
      "Positive or negative",
      "Only positive",
      "Only zero",
      "Always infinite"
    ],
    "answer": "Positive or negative"
  },
  {
    "id": 28,
    "question": "For a tank with inflow but no outflow, the mass balance shows:",
    "options": [
      "Accumulation is zero",
      "Accumulation is equal to inflow",
      "Accumulation is negative",
      "Accumulation is undefined"
    ],
    "answer": "Accumulation is equal to inflow"
  },
  {
    "id": 29,
    "question": "Which of these statements is true for multiple-unit systems?",
    "options": [
      "Overall balances are sufficient to get all details",
      "Unit balances give more detailed stream information",
      "Recycle streams are not considered",
      "Purge streams are not important"
    ],
    "answer": "Unit balances give more detailed stream information"
  },
  {
    "id": 30,
    "question": "When a tank is filled and then drained at equal rates, the system is:",
    "options": [
      "At steady-state",
      "At unsteady-state",
      "Not balanced",
      "At accumulation only"
    ],
    "answer": "At steady-state"
  },
  {
    "id": 31,
    "question": "Which of the following is an advantage of recycle?",
    "options": [
      "Better raw material utilization",
      "Increase in waste",
      "Decrease in yield",
      "Reduction in efficiency"
    ],
    "answer": "Better raw material utilization"
  },
  {
    "id": 32,
    "question": "What is true about purge in recycle systems?",
    "options": [
      "It reduces product purity",
      "It removes accumulated inert gases",
      "It increases energy loss only",
      "It is unnecessary"
    ],
    "answer": "It removes accumulated inert gases"
  },
  {
    "id": 33,
    "question": "In steady-state, the tank level:",
    "options": [
      "Keeps increasing",
      "Keeps decreasing",
      "Remains constant",
      "Fluctuates randomly"
    ],
    "answer": "Remains constant"
  },
  {
    "id": 34,
    "question": "In a bypass system, if 20% of feed bypasses the heater, the outlet temperature:",
    "options": [
      "Will be lower than without bypass",
      "Will be higher than without bypass",
      "Will remain the same",
      "Will become unstable"
    ],
    "answer": "Will be lower than without bypass"
  },
  {
    "id": 35,
    "question": "For a steady-state continuous process:",
    "options": [
      "Input = Output",
      "Input ≠ Output",
      "Accumulation is infinite",
      "No output exists"
    ],
    "answer": "Input = Output"
  },
  {
    "id": 36,
    "question": "Unsteady-state balances are required for:",
    "options": [
      "Startup and shutdown processes",
      "Continuous operations at equilibrium",
      "Processes at constant flow",
      "Processes without feed"
    ],
    "answer": "Startup and shutdown processes"
  } 
]