Answer:
physical change
Explanation:
The evaporation of water is a physical change. When water evaporates, it changes from the liquid state to the gas state, but it is still water; it has not changed into any other substance. All changes of state are physical changes.
Answer:
3.657 kg
Explanation:
Given:
Enthalpy of combustion of hard coal = -35 kJ/g
Enthalpy of combustion of gasoline = 1.28 × 10⁵ kJ/gal
Density of gasoline = 0.692 g/mL
now,
The heat provide 1 gallon of gasoline provide = 1.28 × 10⁵ kJ
and,
heat provided by the 1 gram of coal = 35 kJ
or
1 kJ of heat is provided by (1/35) gram of hard coal
therefore,
For 1.28 × 10⁵ kJ of heat, mass of hard coal = 1.28 × 10⁵ kJ × (1 / 35)
or
For 1.28 × 10⁵ kJ of heat, mass of hard coal = 3657.14 grams = 3.657 kg
Answer:
K.E = 0.5 j
Explanation:
Given data:
Mass of ball = 50 g (50/1000 =0.05 kg)
Speed of ball = 4.5 m/s
K.E of ball = ?
Solution:
Formula:
K.E = 1/2 m.v²
Now we will put the values in formula
K.E = 1/2 (0.05 kg) (4.5 m/s)²
K.E = 1/2 (0.05 kg) 20.25 m²/s²
K.E = 1/2 (1.0 kg. m²/s²)
K.E = 0.5 kg. m²/s²
j = kg. m²/s²
K.E = 0.5 j
Explanation:
Apply Boyle's Law :-
P1V1 = P2V2
- Where P1 is 25 atm
- V1 is 3L
- P2 is 75 atm
- V2 is what we need to find out.
25 × 3 = 75 × V2
<u>So, the answer is d) Part, 1L .</u>
Hope it helps :)
D. All of the other answer choices
In the case of gases, the molar fraction is equivalent to the volume fraction which is also equal to the partial pressure fraction. Therefore, all of the given questions may be answered using the data that has been provided.
