The work done during combustion of 9 × 10-2 kg of ethane, C2H6 (g) at 300 K is (Given R = 8.314 J deg-1 mol-1, atomic mass C = 12, H= 1).
6.236 kJ
-6.236 kJ
18.71 kJ
-18.71 kJ
C.
18.71 kJ
Work done in a chemical reaction,
W = ngRT
where, ng = number of moles of gaseous products - number of moles of gaseous reactants.
Combustion of ethane is-
C2H6 (g) + O2 (g) → 2CO2 (g) + 3H2O (l)
ng = 2 - 4.5 = -2.5
W = (2.5 mol) (8.314 JK-1 mol-1) × 300 K
= 6235.5 kJ = 6.2355 J
Now, 1 mole of C2H6 = 30 gm of C2H6 = 6.2355 kJ
Work done for combustion of 30 gm of C2H6 = 6.2355 kJ
Work done for combustion of 90 gm of C2H6
=
= 18.7065 kJ = 18.71 kJ
The molality of solution containing 15.20 g of urea, (molar mass = 60) dissolved in 150 g of water is
1.689 mol kg-1
0.1689 mol kg-1
0.5922 mo kg-1
0.2533 mol kg-1
Calculate the work done during compression of 2 mol of an ideal gas from a volume of 1 m3 to 10 dm3 300K against a pressure of 100 KPa
-99 kJ
+99 kJ
+22.98 kJ
-22.98 kJ
Which element among the following does form p - p multiple bonds?
Arsenic
Nitrogen
Phosphorus
Antimony
Which of the following statement(s) is/are incorrect for pair of elements Zr-Hf?
Both possess same number of valence electrons
Both have identical sizes
Both have almost identical radii
Both of these belong to same period of periodic table
Solubility of which among the following solids in water changes slightly with temperature?
KNO3
NaNO3
KBr
NaBr
The colour and magnetic nature of manganate ion (MnO) is
green, paramagnetic
purple, diamagnetic
green, diamagnetic
purple, paramagnetic