Let's get to the reaction first ~
Here, we can infer that if we need 1 mole oxygen gas to react with 2 moles Hydrogen gas.
So, the number of Oxygen gas molecules we need to react should be half the number of Hydrogen gas molecules.
Number of Hydrogen gas molecules is :
Number of Oxygen gas molecules needed is :
Number of Oxygen atoms needed :
One atom of Oxygen weight 16 u, so 15 atoms weight ~
So, we need 240 u of Oxygen atoms to react completely with 30 u of Hydrogen atoms.
The number of oxygen atoms = 3
Mass = 24 g
<h3>Further explanation</h3>The formula of a compound shows the composition of the constituent elements
CaCO₃ is composed of 3 types of elements, namely Ca, C and O
The amounts of each of these elements in the compound CaCO₃:
So the number of oxygen atoms = 3
mass of Oxygen :
Answer: a. A solid melts:
b. a vapor is converted to solid:
c. a liquid freezes:
d. A solid sublimes:
e. a vapor condenses to liquid :
f. a liquid boils:
g. dissolving a tablespoon of salt in water:
h. combustion of gasoline:
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy change is negative and vice versa.
a. A solid melts: The solid is converting to liquid, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change is positive.
b. a vapor is converted to solid: The gas is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger Thus the entropy change is negative.
c. a liquid freezes: The liquid is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change is negative.
d. A solid sublimes: The solid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change is positive.
e. a vapor condenses to liquid : The gas is converting to liquid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change is negative.
f. a liquid boils: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change is positive.
g. dissolving a tablespoon of salt in water: The solid is converting to ions , thus the randomness is increasing as the ions can move freely. Thus the entropy change is positive.
h. combustion of gasoline: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change is positive.