valence electrons are the number of electrons in the outer shell. there can only be 8 electrons in the outer shell. The number of valence electrons can be used to determine how many bonds are needed.
For example: H2O
O (oxygen) has 6 valence electrons
H (hydrogen) has 1 valence electron
O needs 2 more electrons to be stable
H needs 1 more electron to be stable
O forms one bond with two H atoms to form H2O.
You can calculate the gram formula mass of this compound by adding the atomic mass of every element in this compound according to the periodic table of elements.
Answer:
Molar mass = [9(12.0)+8(1.01)+4(16.0)] = 180.1 g/mol Moles = 112 g 1 mol x 180.1 g = 0.622 mol (3 sig figs)
Explanation:
Answer:
2H2S + 3O2 → 2SO2 + 2H2O
V(O2) = 48.4 L
p = 105 kPa = 1.036 atm
T = 190 + 273 = 463 K
Ideal gas law:
pV = nRT
n = \frac{pV}{RT}n=
RT
pV
R = 0.08206 L×atm/mol×K
n(O2) = \frac{1.036 \times 48.4}{0.08206 \times 463}=1.319 \; mol=
0.08206×463
1.036×48.4
=1.319mol
According to the reaction:
n(H2S) = \frac{2}{3}
3
2
n(O2) = \frac{2}{3} \times 1.319 = 0.8798 \;mol
3
2
×1.319=0.8798mol
V = \frac{nRT}{p} \\ V(H_2S) = \frac{0.8798 \times 0.08206 \times 463}{1.036}=32.26 \;LV=
p
nRT
V(H
2
S)=
1.036
0.8798×0.08206×463
=32.26L
Answer: 32.26 L
Explanation: