Using boyles law
p1v1=p2v2
v1=3.88
v2=5.43
p1=707
p2=?
707x3.88=p2x5.43
2743.16/5.43=p2
p2=505mmHg
K will give up an electron more easily than Br.
The reaction for burning of charcoal or complete combustion is as follows:

From the above balanced reaction, 1 mole of carbon releases 1 mole of
gas.
Converting mass of charcoal into moles as follows:

Molar mass of pure carbon is 12 g/mol thus,

The same moles of
is released. Converting these moles into mass as follows:
m=n×M
Molar mass of
is 44 g/mol thus,

Converting mass into kg,

Thus, total mass of gas released is 5.5 kg.
Answer:
0.65moles of HCl was produced