a few mc questions(15marks)

Q1.The answer is B
For A,
This is correct.Household bleach contains hypochlorite ion(OCl-) which is the active ingredient of it since it can decolorize a dye by oxidation.
　OCl-(aq) + [dye] → Cl-(aq) + [dye+O]
　　　　　　　　　　　　　　　　　　　　　　　
For B,
This is incorrect since household bleach is produced by mixing Cl2(g) & cold dilute NaOH(aq).It is a mixture of water, sodium chloride & sodium hypochlorite.
　Cl2(g) + 2NaOH(aq) → NaCl(aq) + NaOCl(aq) + H2O(l)
　　　　　　　　　　　　　　　　　　　　　　　
For C,
This is correct.Household bleach can be used as disinfectant as it contains hypochlorite ions which can kill bacteria by giving free oxygen atom
　OCl-(aq) → Cl-(aq) + [O]
　
For D,
This is correct since household bleach is produced by mixing Cl2(g) & cold dilute NaOH(aq).
　　　　　　　　　　　　　　　　　　　　　　　
Q2.The answer is A
　　　　　　　　　　　　　　　　　　　　　　　
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
　　　　　　　　　　　　　　　　　　　　　　　
　No. of mole of Zn
=43.6/65.4
=0.667mol
　　　　　　　　　　　　　　　　　　　　　　　
　No. of mole of HCl
=(375/1000)(1)
=0.375mol
　　　　　　　　　　　　　　　　　　　　　　　
From the equation, the mole ratio of Zn and HCl is 1:2
Therefore, 0.1875mol(=0.375/2) of Zn is enough for the reaction.
　　　　　　　　　　　　　　　　　　　　　　　
HCl is the limited reagent.
No. of mole of H2 = No. of mole of HCl /2
= 0.375/2
=0.1875mol
　　　　　　　　　　　　　　　　　　　　　　　
　Volume of hydrogen liberated
=0.1875 x 24
=4.5dm3