PV = nRT —> P = nRT/V
n = 0.250 moles of gas
R = 0.08206 L atm / mol K
T = 18 + 273 = 291 K
V = 7.50 L
P = (0.250)(0.08206)(291)/(7.50) = 7.96 atm
False subscripts cannot be changed to balance chemical equations
In an ionic bond, one atom essentially donates an electron to stabilize the other atom. The atoms in an ionic bond have different electronegativity values from each other.
While in a covalent bond, the atoms are bound by shared electrons and the electronegativity values are the same.
First, we should get moles acetic acid = molarity * volume
=0.3 M * 0.5 L
= 0.15 mol
then, we should get moles acetate = molarity * volume
= 0.2 M * 0.5L
= 0.1 mol
then, we have to get moles of OH- which added:
moles OH- = molarity * volume
= 1 M * 0.02L
= 0.02 mol
when the reaction equation is:
CH3COOH + OH- → CH3COO- + H2O
moles acetic acid after adding OH- = (0.15-0.02)
= 0.13M
moles acetate after adding OH- = (0.1 + 0.02)
= 0.12 M
Total volume = 0.5 L + 0.02 L= 0.52 L
∴[acetic acid] = moles acetic acid after adding OH- / total volume
= 0.13mol / 0.52L
= 0.25 M
and [acetate ) = 0.12 mol / 0.52L
= 0.23 M
by using H-H equation we can get PH:
PH = Pka + ㏒[salt/acid]
when we have Ka = 1.8 x 10^-5
∴Pka = -㏒Ka
= -㏒ 1.8 x 10^-5
= 4.7
So by substitution:
∴ PH = 4.7 + ㏒[acetate/acetic acid]
= 4.7 + ㏒(0.23/0.25)
= 4.66
Answer:
C) the energy transferred between objects t different temperatures
