How to calculate volume of gas?

MgCO3 --> MgO + CO2

What volume of CO2 (in dm^3) would have been given off when measured at room temperature and pressure?

MgCO3 = 1.47 g

Molar mass of MgCO3 = 84.3 g mol^-1

Please help! I'm really confused...

2 Answers

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  • 7 years ago
    Favorite Answer

    From the equation :

    1 mol MgCO3 will produce 1 mol CO2

    mol MgCO3 = 1.47/84.3 = 0.0174 mol MgCO3

    This will produce 0.0174 mol CO2

    I am always at a loss as to what is meant by "room temperature and pressure". I referred to Wikipedia:

    An unofficial, but commonly used standard is standard ambient temperature and pressure (SATP) as a temperature of 298.15 K (25 °C, 77 °F) and an absolute pressure of 100 kPa (14.504 psi, 0.987 atm).

    Use the gas equation to calculate volume using :

    P = 0.987 atm

    V = ???

    n = mol CO2 = 0.0174

    R = 0.082057

    T = 298.15

    Substitute:

    0.987 * V = 0.0174 * 0.082057*298.15

    V = 0.4266 / 0.987

    V = 0.432 L

    Volume of CO2 produced = 0.432L

  • Bob
    Lv 4
    7 years ago

    1.47 g MgCO3 * (1 mol MgCO3 / 84.3 g MgCO3) = .0174 mol MgCO3

    1 to 1 mol ratio

    mol MgCO3 = mol CO2

    mol CO2 = .0174

    .0174 mol CO2 * (22.4 L / 1 mol CO2) = .390 L CO2

    1 L = 1 dm^3

    .390 dm ^2 = CO2

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