1. (c) Low temperature, high pressure Gases can be liquefied by lowering the temperature and increasing the pressure. Low temperature slows down gas molecules, reducing their kinetic energy, while high pressure forces the molecules closer together, allowing them to form a liquid state. https://www.tiwaRead more

    (c) Low temperature, high pressure
    Gases can be liquefied by lowering the temperature and increasing the pressure. Low temperature slows down gas molecules, reducing their kinetic energy, while high pressure forces the molecules closer together, allowing them to form a liquid state.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-1/

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  2. (c) On increasing pressure and on adding more hydrogen gas to the cylinder (increasing the pressure), the molecules will come closer. Therefore, observations in (i) and (iv) are wrong. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-1/

    (c) On increasing pressure and on adding more hydrogen gas to the cylinder (increasing the pressure), the molecules will come closer. Therefore, observations in (i) and (iv) are wrong.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-1/

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  3. The correct answer is: (a) Vinegar solution. A true solution is a homogeneous mixture where solute particles are completely dissolved in the solvent and cannot be seen under a microscope. Vinegar is a true solution of acetic acid in water, making it a homogeneous mixture. https://www.tiwariacademy.cRead more

    The correct answer is: (a) Vinegar solution. A true solution is a homogeneous mixture where solute particles are completely dissolved in the solvent and cannot be seen under a microscope. Vinegar is a true solution of acetic acid in water, making it a homogeneous mixture.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/

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  4. The correct answer is: (b) NaCl. Common salt, also known as table salt, is primarily composed of sodium chloride (NaCl). It is an ionic compound made of sodium (Na⁺) and chloride (Cl⁻) ions, essential for human health and widely used in food and industry. https://www.tiwariacademy.com/ncert-solutionRead more

    The correct answer is: (b) NaCl. Common salt, also known as table salt, is primarily composed of sodium chloride (NaCl). It is an ionic compound made of sodium (Na⁺) and chloride (Cl⁻) ions, essential for human health and widely used in food and industry.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/

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  5. The correct answer is: (b) (i) and (iii). Pure substances contain only one kind of particles, either atoms or molecules. Pure substances have a uniform composition throughout. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/

    The correct answer is: (b) (i) and (iii).
    Pure substances contain only one kind of particles, either atoms or molecules.
    Pure substances have a uniform composition throughout.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-2/

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