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تجرباتی تکنیکیں

Written by Dr. Ayesha Nadeem (Chemistry)

8 سوالات: گیارہویں جماعت کیمیا، جوابات اور وضاحت کے ساتھ۔

جوابی کنجی کے ساتھ قابلِ پرنٹ ورک شیٹ

تمام سوالات جوابات کے ساتھ
  1. Components of a mixture of liquids with different boiling points are separated by:

    • 1 Sublimation
    • 2 Filtration
    • 3 Fractional distillation
    • 4 Crystallisation
    جواب دیکھیں

    درست جواب: Fractional distillation

    Fractional distillation separates liquids by boiling point.

    غلطی کی اطلاع دیں

  2. In paper chromatography, substances separate because of differences in:

    • 1 Their attraction to the paper and the solvent
    • 2 Density
    • 3 Colour only
    • 4 Mass only
    جواب دیکھیں

    درست جواب: Their attraction to the paper and the solvent

    Components travel at different speeds depending on their affinity to the two phases.

    غلطی کی اطلاع دیں

  3. Pure solid compounds are purified from solutions by:

    • 1 Distillation
    • 2 Centrifuge only
    • 3 Crystallisation
    • 4 Evaporation to dryness only
    جواب دیکھیں

    درست جواب: Crystallisation

    Crystallisation gives pure crystals from a saturated solution.

    غلطی کی اطلاع دیں

  4. The Rf value in chromatography is the ratio of:

    • 1 Solvent to substance
    • 2 Distance moved by substance to distance moved by solvent
    • 3 Temperature to time
    • 4 Mass of substance to solvent
    جواب دیکھیں

    درست جواب: Distance moved by substance to distance moved by solvent

    Rf = distance of spot / distance of solvent front.

    غلطی کی اطلاع دیں

  5. Solvent extraction works because a solute is:

    • 1 A gas
    • 2 Always ionic
    • 3 A catalyst
    • 4 More soluble in one solvent than another
    جواب دیکھیں

    درست جواب: More soluble in one solvent than another

    The solute moves into the solvent in which it dissolves better.

    غلطی کی اطلاع دیں

  6. Which technique separates a mixture of two liquids that do not mix?

    • 1 Sublimation
    • 2 Crystallisation
    • 3 Separating funnel
    • 4 Filtration
    جواب دیکھیں

    درست جواب: Separating funnel

    The denser liquid is drained off.

    غلطی کی اطلاع دیں

  7. Sublimation is used to separate:

    • 1 Sugar from water
    • 2 Oil from water
    • 3 Iodine from sand
    • 4 Salt from water
    جواب دیکھیں

    درست جواب: Iodine from sand

    Iodine changes directly to a gas on heating.

    غلطی کی اطلاع دیں

  8. Filtration separates:

    • 1 Two liquids
    • 2 Two gases
    • 3 An insoluble solid from a liquid
    • 4 Dissolved salts
    جواب دیکھیں

    درست جواب: An insoluble solid from a liquid

    The filter paper traps the solid.

    غلطی کی اطلاع دیں

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