Answer:
second law of thermodynamics.
Explanation:
The second law of thermodynamics deals with interconversion of energy from one form to another. Although energy can be converted from one form to another, this conversion is never 100% efficient because energy is lost in certain ways such as through heat. In a combustion engine, it is not possible to recover the energy from the gasoline 100% since energy must be lost along the way via such means as heat losses. Hence I will be skeptical about such an advert.
Answer:
Percentage yield = 0.49 × 10² %
Explanation:
Given data:
Actual yield of SO₂ = 4.309 ×10² g
Theoretical yield of SO₂ = 8.78 ×10² g
Percentage yield = ?
Solution:
Chemical equation:
2NiS₂ + 5O₂ → 2NiO + 4SO₂
Percentage yield:
Percentage yield = actual yield / theoretical yield × 100
Percentage yield = 4.309 ×10² g / 8.78 ×10² g × 100
Percentage yield = 0.491 × 100
Percentage yield = 49.1%
In scientific notation:
Percentage yield = 0.49 × 10² %
Answer: 0.14 kg
Explanation:
Gourmet chocolate candy contains 7.00 g of dietary fat in each 22.7-g piece
That is 1 piece of candy weighs 22.7 g and contains 7.00 g of dietary fat
Converting the mass in pounds to kg
1 lb = 0.45 kg = 450 grams (1kg=1000g)
Number of pieces = 
1 piece contains = 7 g of dietary fat
Thus 30 pieces would contain =
of dietary fat
1 g = 0.001 kg
Thus 140 grams =
Thus 0.14 kg of dietary fat are in a box containing 1.00 lb of candy.
The molecule with same molecular formula but different arrangement of atoms is said to be an isomer.
When 2,2-dimethylbutane reacts with chlorine in the presence of light gives three isomers that is 
(3-chloro-2,2-dimethylbutane), 
(1-chloro-2,2-dimethylbutane) and 
(1-chloro-3,3-dimethylbutane).
In above case, the molecular formula of all isomers are same i.e.
but chlorine is arranged in different positions of carbon. Thus, results isomers.
The reaction is shown in the image.
