In the reaction mg (s) + 2hcl (aq) h2 (g) + mgcl2 (aq), how many moles of hydrogen gas will be produced from 75.0 milliliters of a 1.0 m hcl in an excess of mg?

HCl is limiting reactant, Mg in excess therefore:

number of moles HCl:

75.0 mL in liters: 75.0 / 1000 => 0.075 L

Molarity HCl = 1.0 M

n = M x V

n = 1.0 x 0.075 

n = 0.075 moles of HCl

Mg(s) + 2 HCl (aq) = H2 (g) + MgCl2 (aq)

2 moles HCl   1 mole H2
0.075 moles of HCl ( moles H2)

moles H2 = 0.075 x 1 / 2

moles H2 = 0.075 / 2

= 0.0375 moles of H2

hope this helps!

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.