A chemist reacts magnesium with hydrochloric acid and collects 57.48 mL of the hydrogen gas that is produced by water displacement. If the lab temperature is 24 C and the atmospheric pressure is 742.1 mm Hg, how many grams of hydrogen are produced? Water vapor pressure is 22.4 mm Hg at 24 C.

0.00446 grams of hydrogen are produced.

Explanation:

Atmospheric pressure at which hydrogen gas was collected = p

p = 742.1 mmHg

Vapor pressure of the hydrogen gas = p' = 22.4 mmHg

Pressure of the hydrogen gas = P

P = p - p' = 742.1 mmhg - 22.4 mmhg = 719.7 mmHg

719.7 mmHg =

1 atm = 760 mmHg

Volume of the hydrogen gas ,V = 57.48 mL = 0.05748 L

1 mL =0.001 L

Temperature of the hydrogen gas = T = 24°C=24+ 273 K = 297 K

Moles of hydrogen gas = n

( Ideal gas equation)

n = 0.00223 mol

Mass of 0.00223 moles of hydrogen gas:

0.00223 mol × 2 g/mol = 0.00446 g

0.00446 grams of hydrogen are produced.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.