Answer:
C
Explanation:
The oxidation number of Sulphur in SO4^2- is;
x + 4(-2) = -2
x - 8 = -2
x = -2 + 8
x = 6
Now,
the oxidation number of sulphur in H2SO3 is
2 (1) + x + 3(-2) = 0
2 + x -6 = 0
-4 + x = 0
x = 4
Hence, the oxidation number of sulphur changed from +6 to +4 which signifies gain of two electrons as shown in option C.
Correct Answer: Option B: <span>whether the particles do not settle for an extended period of time
Reason:
Particle size in colloidal solution ranges from 1-100 nm, while that is suspension is more than 100 nm. Due to large particle size, particles in suspension settle down, upon standing for long. Thus, the best </span>criteria determine whether a heterogeneous mixture is a colloid or a suspension is to check <span>whether the particles do not settle for an extended period of time</span>
N(NaCl)=8 moles
M(NaCl)=A(Na)+A(Cl)
M(NaCl)=22.99+35.45=58.44 g/moles
m(NaCl)=n(NaCl)·M(NaCl)
m(NaCl)=8moles·58.44g/moles=467.52 g
