The strong Base with a pH of 12 is reduced by 4 units upon being added with solution Y. If you added a strong acid to the strong base, all ions are present in the solution, yes? So every OH- is neutralised by every H+ for example, meaning the resultant pH should be 7. The resultant pH is only 8 however, so solution Y must be a <em>weak acid </em>only!
Answer: A balloon is charged by a process of frictional charging and the object is getting charged by the process of induction.
Explanation:
When two bodies are rubbed against each other, charging by friction or rubbing occurs. The electropositive object loses electrons to electronegative object. Thus, when balloon is rubbed on a wall, it becomes charged.
The charged balloon is able to attract an uncharged object by inducing charge on it without the two objects touching each other. Electrostatic force acts between two charged objects. Charged balloon causes electrons to move at one end thereby inducing opposite charge in the object and thus, charged balloon is able to attract uncharged object.
The balanced chemical equation for the above reaction is as follows;
2Ca + O₂ --> 2CaO
stoichiometry of Ca to O₂ is 2:1
this means that 2 mol of Ca reacts with 1 mol of O₂.
If O₂ is the limiting reactant,
4 mol of O₂ should react with (4x2) - 8 mol of Ca
however only 7.43 mol of Ca is present. Therefore Ca is the limiting reactant.
7.43 mol of Ca reacts with - 7.43/2 = 3.715 mol of O₂
therefore there's excess O₂₂ remaining after the reaction
Since Ca is the limiting reactant, it is fully used up in the reaction and there is no Ca remaining after the reaction is completed.
