<span>The
three states of matter are solid, liquid and gas phase. The solid has a more
definite shape and volume. The particles are locked into place. It cannot be
further compressed due to the bond that exists between the molecules. The
kinetic energy of the molecules is close to none because the molecules are so
close and so compact with each other. For liquids, it has a medium shape and
volume. The particles can move or slide past each other due to the small space
available for movement. It cannot be compressed further due to the repulsive
forces that acts between them. The kinetic energy is medium. For gases, it has
no shape and volume because the particles can move freely from one other. Their
collisions are rare due to the distance between them. The kinetic energy of the
molecules is high because there is room for movement. It can be compressed easily.</span>
Answer:
It is a chemical change.
Explanation:
A tree burning down would be a chemical change because the composition of the tree is what changes, not just the physical characteristics.
Answer:
Mass of benzene required = 0.78 g
Explanation:
Given data:
Mass of CO₂ produced = 2.66 g
Mass of benzene required = ?
Solution:
Chemical equation:
2C₆H₆ + 15O₂ → 6H₂O + 12CO₂
Number of moles of CO₂:
Number of moles = mass/molar mass
Number of moles = 2.66 g/ 44 g/mol
Number of moles = 0.06 mol
Now we will compare the moles of CO₂ with C₆H₆.
CO₂ : C₆H₆
12 : 2
0.06 : 2/12×0.06=0.01 mol
Mass of benzene required:
Mass = number of moles × molar mass
Mass = 0.01 mol × 78.11 g/mol
Mass = 0.78 g
Note that
The heating value of standard coal is about 30,080 kJ/kg
1 L of water has a mass of 1.0 kg
The mass of 15 L of water = 15 kg.
The latent heat of vaporization of water is about 2260 kJ/kg,
The energy required to boil 15 L of water is
(2260 kJ/kg)*(15 kg) = 33900 kJ
The mass of coal required to provide this energy is
(33900 kJ)/(30080 kJ/kg) = 1.127 kg
Because 1 kg = 2.205 lb, the mass of coal required is
(1.127 kg)*(2.205 lb/kg) = 2.485 lb
Answer: 2.49 lb (nearest hundredth)
fluorineelement has 9 electrons, and 11 neutrons