a 2.17 gm sample barium reacted completely with water what is the equation for the reaction how many milliliters of dry H2 evoled at 21degree celcius and 748mm of Hg? solution

400 mL

Explanation:

Given dа ta:

Mass of barium = 2.17 g

Pressure = 748 mmHg (748/760 = 0.98 atm)

Temperature = 21 °C (273 + 21 = 294k)

Milliliters of H₂ evolved = ?

Solution:

chemical equation:

Ba + 2H₂O → Ba (OH) ₂ + H₂

Number of moles of barium:

Number of moles = mass / molar mass

Number of moles = 2.17 g / 137.327 g/mol

Number of moles = 0.016 mol

Now we will compare the moles of barium with H₂.

Ba : H₂

1 : 1

0.016 : 0.016

Milliliters of H₂:

PV = nRT

V = nRT/P

V = 0.016 mol * 0.0821 atm. mol⁻¹. k⁻¹. L*294 k/0.98 atm

V = 0.39 atm. L/0.98 atm

V = 0.4 L

L to mL

0.4 * 1000 = 400 mL