Question

Calculate the amount of heat ( in kJ) required to convert 344.0
g of liquid water at 22.5 oC into steam at 145.0
**°**C. ( Heat of vaporization of water at its boiling
point = 40.7 kJ/mol., specific heats of water and steam are 4.184
J/g **°**C and 2.01 J/g **°**C,
respectively. )

Answer #1

Ti = 22.5 oC

Tf = 145.0 oC

here

Cl = 4.184 J/g.oC

Heat required to convert liquid from 22.5 oC to 100.0 oC

Q1 = m*Cl*(Tf-Ti)

= 344 g * 4.184 J/g.oC *(100-22.5) oC

= 111545.44 J

Lv = 40.7KJ/mol =

40700J/mol

Lets convert mass to mol

Molar mass of H2O = 18.016 g/mol

number of mol

n= mass/molar mass

= 344.0/18.016

= 19.0941 mol

Heat required to convert liquid to gas at 100.0 oC

Q2 = n*Lv

= 19.0941 mol *40700 J/mol

= 777131.4387 J

Cg = 2.01 J/g.oC

Heat required to convert vapour from 100.0 oC to 145.0 oC

Q3 = m*Cg*(Tf-Ti)

= 344 g * 2.01 J/g.oC *(145-100) oC

= 31114.8 J

Total heat required = Q1 + Q2 + Q3

= 111545.44 J + 777131.4387 J + 31114.8 J

= 919792 J

= 920. KJ

Answer: 920. KJ

What amount of thermal energy (in kJ) is required to convert 220
g of ice at -18 °C completely to water vapour at 248 °C? The
melting point of water is 0 °C and its normal boiling point is 100
°C. The heat of fusion of water is 6.02 kJ mol-1 The heat of
vaporization of water at its normal boiling point is 40.7 kJ mol-1
The specific heat capacity of ice is 2.09 J g-1 °C-1 The specific
heat...

What amount of thermal energy (in kJ) is required to convert 216
g of ice at -30 °C completely to water vapour at 198 °C? The
melting point of water is 0 °C and its normal boiling point is 100
°C. The heat of fusion of water is 6.02 kJ mol-1 The heat of
vaporization of water at its normal boiling point is 40.7 kJ mol-1
The specific heat capacity of ice is 2.09 J g-1 °C-1 The specific
heat...

1. Calculate the amount of heat required to convert 1 g of
liquid water at 67°C to steam at 100°C. The specific heat of liquid
water is 4.18 J/g°C and the heat of vaporization is 40.7
kJ/mol.
2400 J
2.2 kJ
8.31 J
22.6 kJ
40.8 kJ
2. Which one of the following is true about surfactants?
they act to decrease surface tension
they form micelles on the surface of water
none of these
they are generally very small, highly...

How much heat (in kJ) is required to convert 420. g of liquid
H2O at 24.9°C into steam at 145°C? (Assume that the specific heat
of liquid water is 4.184 J/g·°C, the specific heat of steam is
2.078 J/g·°C, and that both values are constant over the given
temperature ranges. The normal boiling point of H2O is
100.0°C.)

How much heat (in kJ) is required to convert 420. g of liquid
H2O at 24.5°C into steam at 146°C? (Assume that the
specific heat of liquid water is 4.184 J/g·°C, the specific heat of
steam is 2.078 J/g·°C, and that both values are constant over the
given temperature ranges. The normal boiling point of
H2O is 100.0°C.)

1.Calculate the amount of energy (in kJ) necessary to convert
377 g of liquid water from 0 degree C to water vapor at 167 degress
C. The molar heat of vaporization (Hvap) of
water is 40.79 kJ/mol. The specific heat for water is 4.184 J/g
degrees C, and for steam is 1.99 J/g degrees C. (Assume that the
specific heat values do not change over the range of temperatures
in the problem.)
2.Which substance has the highest vapor pressure at...

Calculate the amount of heat energy
required to convert 15.0 g of water at 60.5oC to steam
at 124.0°C.
(Cwater =
4.18 J/g°C; Csteam = 2.02 J/g°C; molar heat of
vaporization of liquid water = 4.07 ´ 104 J/mol)

What amount of heat (in kJ) is required to convert 25.2 g of an
unknown liquid (MM = 83.21 g/mol) at 19.2 °C to a gas at 93.5 °C?
(heat capacity of liquid = 1.58 J/g･°C; heat capacity of gas =
0.932 J/g･°C; ∆Hvap = 22.5 kJ/mol; Tb = 57.3°C) Please answer with
the correct significant figures.

Calculate the amount of energy (in kJ) required to heat
10.0 g of water from 50.0°C to 150.°C at constant pressure.
(specific heat capacity of liquid water is 4.18
J/g⋅K; specific heat capacity of water vapor is
1.84 J/g⋅K; heat of vaporization of water is 2.260
kJ/g).
(1) 16.2 kJ (2) 25.6 kJ (3) 5.4 kJ (4) 33.2 kJ (5) 1.6
kJ
I know that the answer is (2) 25.6 KJ but I do not know how to
get to...

How much heat energy is required to convert 21.1 g of solid
ethanol at -114.5 °C to gaseous ethanol at 191.5 °C? The molar heat
of fusion of ethanol is 4.60 kJ/mol and its molar heat of
vaporization is 38.56 kJ/mol. Ethanol has a normal melting point of
-114.5 °C and a normal boiling point of 78.4 °C. The specific heat
capacity of liquid ethanol is 2.45 J/g·°C and that of gaseous
ethanol is 1.43 J/g·°C.
________kJ

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 13 minutes ago

asked 13 minutes ago

asked 32 minutes ago

asked 43 minutes ago

asked 43 minutes ago

asked 44 minutes ago

asked 59 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago