The reagent neutral ferric chloride is used to detect the presence of ______________

Blister copper is produced by reaction of copper oxide with copper sulphide.

2Cu₂O + Cu₂S $$\to$$ 6Cu + SO₂

When 2.86 $$\times$$ 10³ g of Cu₂O and 4.77 $$\times$$ 10³ g of Cu₂S are used for reaction, the mass of copper produced is _____________ g. (nearest integer)

(Atomic mass of Cu = 63.5 a.m. u, S = 32.0 a.m. u, O = 16.0 a.m. u)

Amongst the following, the number of molecule/(s) having net resultant dipole moment is ____________.

NF₃, BF₃, BeF₂, CHCl₃, H₂S, SiF₄, CCl₄, PF₅

1.0 mol of monoatomic ideal gas is expanded from state 1 to state 2 as shown in the figure. The magnitude of the work done for the expansion of gas from state 1 to state 2 at 300 K is ____________ J. (Nearest integer)

(Given : R = 8.3 J K^$$-$$1 mol^$$-$$1, ln10 = 2.3, log2 = 0.30)