The balanced chemical equation below represents the formation of magnesium chloride. Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g)

At STP, what is the total number of liters of hydrogen gas produced when 3.00 moles of hydrochloric acid solution-HCl(aq) is completely consumed?
A.22.4 L

B.11.2 L

C.33.6 L

D.44.8

C. 33.6L

Explanation:

Based on the reaction, 2 moles of HCl reacts producing 1 mole of hydrogen.

To solve this question we must find the moles of hydrogen produced using the reaction. Then, with combined gas law (PV = nRT) we can find the volume produced:

Moles H2:

3.00 moles HCl * (1mol H2 / 2mol HCl) = 1.50 moles H2 are produced

Volume:

PV = nRT

V = nRT / P

Where P is pressure = 1atm at STP

V is volume = Our incognite

n are moles of the gas = 1.50 moles

R is gas constant = 0.082atmL/molK

T is absolute temperature = 273.15K

V = nRT / P

V = 1.50mol*0.082atmL/molK*273.15K / 1atm

V = 33.6L

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.