The heat of combustion of ethane gas is 373 K Cal per mole. Assuming that 50% of heat is lost, how many litres of ethane measured at S.T.P. must be burnt to convert 50 kg of water at `10^@C` to steam at `100^@C`? One mole of gas occupies 22.4 litres at S.T.P. Latent heat (L) of steam ` = 2.25 xx 10^6 J k^-1`.

A thermocole box is a cheap and effieicnet method for storing small quantity of cooked food in summer in particular. A cubical box of side 30 cm has a thickness of 5 cm. If 4 kg of ice are put in a box. Estimate the amount of ice remaining after 6 h. The outside temperature 45^@C , and coefficient K = 0.01 J s^-1 m^-1 k^-1 [Heat of fusion of water = 335 xx 10^3 J kg^-1] .

A geyser heats water flowing at the rate of 3.0 litres per minute from 27 ^@C to 77 ^@C . If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combustion is 4.0 xx 10^4 J//g ?

One mole of H_2 gas is contained in a box of volume V = 1.00 m^3 at T = 300 K . The gas is heated to a temperature of T = 3000K and the gas gets converted to a gas of hydrogen atoms. The final pressure would be (considering all gases of be ideal)

Gasoline has an enthalpy of combustion 24000 kJ/mol gallon. When gasoline burns in an automobile engine, approximately 30% of the energy released is used to produce mechanical work. The remainder is lost as heat transfer to the engine's cooling system. As a start on estimating how much heat transfer is required, calculate what mass of water could be heated from 25^(@)C to 75^(@)C by the combustion of 1.0 gallon of gasoline in an automobile? (Given : C(H_(2)O)=4.18 J//g^(@)C ) a) 34.45 kg b) 80.383 kg c) 22 kg d) 224 kg

The graph of compressibility factor (Z) vs. P for one mole of a real gas is shown in following diagram. The graph is plotted at constant temperature 273K. If the slope of graph at very high pressure ((dZ)/(dP)) is ((1)/(2.8))atm^(-1) , then calculate volume of one mole of real gas molecules (in L/mol) Given : N_(A)=6xx10^(23) and R=(22.4)/(273)L atmK^(-1)mol^(-1)

One mole of an ideal gas at 25^(@)C expands in volume from 1.0 L to 4.0 L at constant temperature. What work (in J) is done if the gas expands against vacuum (P_("external") = 0) ?

The forward rate constant for the elementary reversible gaseous reaction C_(2)H_(6)ltimplies2CH_(3) "is" 1.57xx10^(-3)s^(-1)at 100 K What is the rate constant for the backward reaction at this temperature if 10^(-4) moles of CH_(3) and 10 moles of C_(2)H_(6) are present in a 10 litre vessel at equilibrium . a) 1.57xx10^(9) L "mole"^(-1)s^(-1) b) 1.57xx10^(10) L "mole"^(-1)s^(-1) c) 1.57xx10^(11) L "mole"^(-1)s^(-1) d) 1.57xx10^(7) L "mole"^(-1)s^(-1)

A 10 kW drilling machine is used to drill a bore in a small aluminium block of mass 8.0 kg. How much is the rise in temperature of the block in 2.5 minutes, assuming 50% of power is used up in heating the machine itself or lost to the surroundings. Specific heat of aluminium = 0.91 J g^-1 ^@C^-1

What is the change in entropy when 2.5 mole of water is heated from 27^(@)C to 87^(@)C ? Assume that the heat capacity is constant (C_(p))_(m)(H_(2)O)=4.2J//gK, ln(1.2)=0.18)

Surface tension is exhibited by liquids due to force of attraction between molecules of the liquid. The surface tension decreases with increase in temperature and vanishes at boiling point. Given that the latent heat of vaporation for water rho_(w) = 540kcal/kg ,mechanical equivalent heat =4.2j/cal Avogadro's No. N_A = 6.0 xx 10^26 , and the molecular weight of water M_A = 18 kg for 1 k mole. Estimate the energy required for oe molecule of water to evaporate.