The balanced reaction is as follows;
BiCl₂ + Na₂SO₄ --> 2NaCl + BiSO₄
this is a double displacement reaction
the oxidation number of Bi is +2 in both BiCl₂ and BiSO₄
oxidation number of Cl is -1 in both BiCl₂ and NaCl
oxidation number of Na is +1 in both Na₂SO₄ and NaCl
oxidation numbers of elements in SO₄²⁻ remains the same in both compounds.Therefore the oxidation state in any of the elements in the reaction doesn't change. Neither of the elements show an increase or decrease in the oxidation numbers .
Answer for this question is no element decreases its oxidation number.
The extraction is done by electrolysis. The ions in the aluminium oxide must be free to move so that electricity can pass through it. Aluminium oxide has a very high melting point (over 2000°C) so it would be expensive to melt it. The use of cryolite reduces some of the energy costs involved in extracting aluminium.
Answer is: molarity is 0,155 M.
V(solution) = 90,0 mL = 0,09 L.
ω(NaCl) = 0,92% ÷ 100% = 0,0092.
d(solution) = 1 g/mL.
m(solution) = V(solution) · d(solution).
m(solution) = 90 mL · 1 g/mL = 90 g.
m(NaCl) = 90 g · 0,0092 = 0,828 g.
n(NaCl) = 0,828 g ÷ 58,4 g/mol.
n(NaCl) = 0,014 mol.
c(solution) = 0,014 mol ÷ 0,09 L.
c(solution) = 0,155 mol/L.
Answer:
134.8 seconds is the half-life (in seconds) of the reaction for the initial 
concentration
Explanation:
Half life for second order kinetics is given by:
Integrated rate law for second order kinetics is given by:
= half life
k = rate constant
= initial concentration
a = Final concentration of reactant after time t
We have :
Initial concentration of ![C_2F_4=[a_o]=\frac{0.438 mol}{2.42 L}=0.1810 mol/L](https://tex.z-dn.net/?f=C_2F_4%3D%5Ba_o%5D%3D%5Cfrac%7B0.438%20mol%7D%7B2.42%20L%7D%3D0.1810%20mol%2FL)
Rate constant = k = 
134.8 seconds is the half-life (in seconds) of the reaction for the initial concentration
