The volume of hydrogen gas that evolved is calculated as follows
by use of ideal gas equation
that is PV = nRT
P=745 mm hg
V= ?
R(gas constant)= 62.36 L.mm hg/mol.k
T= 20 + 273 = 293 k
n=number of moles which is calculated as follows
find the moles of Na used
= 0.52/23=0.023 moles
write the reacting equation
2Na +2H2O =2NaOH +H2
by use of reacting ratio between Na : H2 which is 2:1 therefore the mole of H2 = 0.023/2 =0.0115 moles
by making the volume the subject of the formula
v=nRT/P
V= (0.0115 x 62.36 x 293) / 745 = 0.283 L
True ^^ they explained it well
I think it may be A.
But I'm not sure
Kw = 1.219x10⁻¹⁴
kw = [H⁺] x [OH⁻]
in water [H⁺] = [OH⁻] therefore:
[H⁺] = √ kw
[H⁺] = √ <span>1.219x10⁻¹⁴
[H</span>⁺] = 1.104x10⁻⁷
pH = - log [H⁺]
pH = - log [ <span>1.104x10⁻⁷ ]
pH = 6.95
hope this helps!</span>
The vapor pressure (in torr) of a 35°C solution : 52 torr
<h3>Further explanation</h3>
Given
x propanol = 0.75
P°ethanol=100 torr
P°propanol=36 torr
Required
the vapor pressure
Solution
Raoult's Law
P solution = xA.P°A +xB.P°B
x ethanol = 1- 0.75 = 0.25
Input the value :
P solution = 0.25 x 100 + 0.75 x 36
P solution = 25 + 27
P solution = 52 torr
