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    Gas Laws & Heat Of Reaction

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    1.
    For the reaction
    2 NO(g) + O2(g) -->2 NO2(g)
    deltaH = -126.0 kJ at 25C.

    (a) Calculate the amount of heat transferred when 333 g of NO(g) reacts with O2(g) at 25C and 1 atm.
    (b) Does this heat flow into the system or does it flow to the surroundings?
    (c) Is this reaction exothermic or endothermic?

    2.
    If 8675 J of heat flows into 135.0 g of water initially at 20.0C, find the final temperature of
    the water. The specific heat of water is 4.18 J g^-1 K^-1.

    3.
    Find the molecular weight of a gas if 22.24 g of the gas in a 7045 cm^3
    container at 20°C exerts a pressure of 698 torr.

    CONSTANTS
    R = 0.08206 L atm mol^-1 K^-1
    1 atm = 760 torr
    c = 3.00 x 10^8 m/s
    h = 6.63 x 10^-34 J . s

    4.
    Calculate deltaH at 25C is -1790 kJ for the reaction
    C3H6O(l) + 4O2(g) -->3 CO2(g) + 3 H2O(l)

    Given these f deltaH values at 25C: -394 kJ/mol for CO2(g), -286 kJ/mol for H2O(l), and 0 for
    O2(g), find f deltaH for C3H6O(l).

    5.
    What volume of H2(g) at 27C and 1.08 atm is produced when
    45.3 g of Al reacts as follows:

    2Al + 6HNO3(aq) --> 2Al(NO3)3 + 3H2

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    https://brainmass.com/chemistry/energetics-and-thermodynamics/gas-laws-heat-of-reaction-538109

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    Solution Preview

    1.

    For the reaction

    2 NO(g) + O2(g) 2 NO2(g)
    H= -126.0 kJ at 25C.

    (a) Calculate the amount of heat transferred when 333 g of NO(g) reacts with O2(g) at 25C and 1 atm.
    The molar amount of NO: 333/30.01=11.0963 mol
    Heat produced: 126.0/2*11.0963=699.07 kJ

    (b) Does this heat flow into the system or does it flow to the surroundings?
    Since delta H is negative, it flows to the surroundings.
    (c) Is this reaction exothermic or ...

    Solution Summary

    The great laws and heat of reactions are examined.

    $2.19