Question

Find the amount of heat required to heat
1-5 litres of water from 30°c to 75°C.(Specific
heat of water = 4200 J/kg-k).​

Answer 1

Answer:

282.555

Explanation:

Mass of

1.5 L

water is

Mass = Volume × Density

=

1.5

L

×

1000

g

L

=

1500

g

Now, use this equation

Q = mSΔT

Where

m =

Mass of sample

S =

Specific heat capacity of sample (

4.186 J/g°C

for water)

ΔT =

Change in temperature of sample

Q

=

1500

g

×

4.186

J

g

°C

×

(

75

−

30

)

°C

=

282555

J

=

282.555

kJ

Answer 2

Explanation:

Energy required to heat 1.5 kg water from 20 degrees C to 80 degrees C.

Specific heat of water = 1 cal/gram-deg C

1.5 kg = 1,500 grams.

Energy required = 1500 * 60 * 1

= 90,000 calories = 90 kcal.

1 kilocalorie = 4184 joules

Energy required = 90 * 4184

= 376,560 joules = 376.6 joules