When 5.1 g of solid NH₄HS is introduced into a two litre evacuated flask at 27$$^\circ$$C, 20% of the solid decomposes into gaseous ammonia and hydrogen sulphide. The K_p for the reaction at 27$$^\circ$$C is x $$\times$$ 10^$$-$$2. The value of x is _____________. (Integer answer) [Given R = 0.082 L atm K^$$-$$1 mol^$$-$$]

The number of species having non-pyramidal shape among the following is ___________.

(A) SO₃

(B) NO$$_3^ - $$

(C) PCl₃

(D) CO$$_3^{2 - }$$

Data given for the following reaction is as follows :

FeO_(s) + C_(graphite) $$\to$$ Fe_(s) + CO_(g)

Substance	$$\Delta H^\circ $$ (kJ mol$$^{ - 1}$$)	$$\Delta S^\circ $$ (J mol$$^{ - 1}$$ K$$^{ - 1}$$)
$$Fe{O_{(s)}}$$	$$ - 266.3$$	57.49
$${C_{(graphite)}}$$	0	5.74
$$F{e_{(s)}}$$	0	27.28
$$C{O_{(g)}}$$	$$ - 110.5$$	197.6

The minimum temperature in K at which the reaction becomes spontaneous is ___________. (Integer answer)

The angle between the straight lines, whose direction cosines are given by the equations 2l + 2m $$-$$ n = 0 and mn + nl + lm = 0, is :