How many joules of heat are required to heat 25.0 g of isopropyl alcohol from the prevailing room temperature, 21.2 oC, to its b
1 answer:
Answer:
3984.12 J joules of heat are required to heat 25.0 g of isopropyl alcohol to its boiling point.
Explanation:
Where:
Q = heat absorbed or heat lost
c = specific heat of substance
m = Mass of the substance
ΔT = change in temperature of the substance
= Initial temperature of the substance
= Final temperature of the substance
We have mass of isopropyl alcohol = m = 25.0 g
Specific heat of isopropyl alcohol = c = 2.604 J/g°C
Initial temperature of the isopropyl alcohol =
Final temperature of the isopropyl alcohol =
Heat absorbed by the isopropyl alcohol to boil:
3984.12 J joules of heat are required to heat 25.0 g of isopropyl alcohol to its boiling point.
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Answer : Part a) Fraction of energy lost : 20 %
Part b) Speed before and after bounce = 6.3 m/s and 5.6 m/s
Part c) Energy is lost as thermal energy .
Part A) Fraction of energy lost during bouncing :
The energy possessed by any object when present at any height is potential energy . The formula of potential energy is given as :
PE = mgh
where PE = potential energy
,m = mass pf object , g = gravitational acceleration and h = height
Given : Initial height , h₁ = 2 m final height , h₂ = 1.6 m
Initial potential energy : m * g* h ₁
Final potential energy = m* g* h₂
Energy lost = Initial PE - Final PE
= ( mgh₁ - mgh2 )
Fraction of energy lost :
Plugging value in above formula and taking " mg " common =>
Fraction of energy lost =
Fraction of energy lost = 20%
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Part B ) Speed of ball just before and after the bounce.
Speed of ball before the bounce :
The potential energy gets converted to kinetic energy when it fall from height of 2m , so
Potential energy = kinetic energy
mgh₁ = m v²
or v ² = 2gh₁
Given : g = 9.8 m/s² h= 2 m
v² = 2 * 9.8 m/s² * 2 m = 39.2 m²/s²
v = 6.3 m/s
Speed of ball after bounce :
Potential energy = kinetic energy
mgh₂ = m v²
or v² = 2gh₂
= 2 * 9.8 m/s² * 1.6 m = 31.36 m²/s²
v = 5.6 m/s
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Part C) The energy lost due to friction. When the ball touches the ground , there occur friction force between the surface of ground and ball , due to which energy is lost as thermal energy .
Answer:
The distance between the centers of the two oxygen atoms in an oxygen molecule is
Explanation:
We know, 1 inch = 2.54 cm
So,
=
So the distance between the centers of the two oxygen atoms in an oxygen molecule is