(a) (i) Zinc blende is mainly Zinc sulphide and in industry it is converted to ZnO by flames to burn off the sulphur as SO2 which is then used to make sulphuric acid.
(ii) Reduction of ZnO to Zn:-
2ZnO + C = CO2 + 2Zn
(b) This is called sacrificial anodic protection. The zinc ( which is more reactive than iron) when in contact with the oxygen in the air is oxidised and in the process loses its electrons. These travel through the electrolyte to the iron. The electrons then reduce any iron oxide to iron: fe2+ + 2e ---> Fe.
Answer:
Solutions in water are especially common, and are called aqueous solutions. Non-aqueous solutions are when the liquid solvent involved is not water.
Answer:
36000 centimeters
Explanation:
If the average speed of a species of tortoise is 0.36 km/h, then it would be 36000 centimeters.
Answer:
0.11mol/dm³
Explanation:
The reaction expression is given as:
HCl + NaOH → NaCl + H₂O
Volume of acid = 25cm³ = 0.025dm³
Volume of base = 18.4cm³ = 0.0184dm³
Concentration of base = 0.15mol/dm³
Solution:
The concentration of hydrochloric acid = ?
To solve this problem, let us first find the number of moles of the base;
Number of moles = concentration x volume
Number of moles = 0.15mol/dm³ x 0.0184dm³ = 0.00276mol
From the balanced reaction equation;
1 mole of NaOH will combine with 1 mole of HCl
Therefore, 0.00276mol of the base will combine with 0.00276mol of HCl
So;
Concentration of acid = 
= 
= 0.11mol/dm³
