Answer:
A liquid-fueled rocket has two liquids (liquids are good because of the density, they need less space than a gas to be stored), such that these liquids are called the fuel and the oxidizer.
These liquids are injected into a system that leads to a combustion chamber, where the liquids are mixed (we need to mix the fuel with the oxidizer to enable the combustion of the fuel) and burned to produce thrust.
Some common examples of oxidizers are liquid oxygen, which may be combined with fuels like liquid hydrogen, liquid methane, kerosene and hydrazine.
Other oxidizers are liquid fluorine (which also can be combined with the fuels liquid hydrogen and hydrazine), nitrogen tetroxide (which can be combined whit kerosene, hydrazine and other fuels) and FLOX-70, which can only be combined with kerosene.
The "most commonly used" may depend on the country and the type of liquid propellant ( petroleum, cryogens, and hypergols)
Such that the most common oxidizer may be liquid oxygen, and the most common fuel the kerosene.
Answer:
4.5 moles of lithium sulfate are produced.
Explanation:
Given data:
Number of moles of lead sulfate = 2.25 mol
Number of moles of lithium nitrate = 9.62 mol
Number of moles of lithium sulfate = ?
Solution:
Chemical equation:
Pb(SO₄)₂ + 4LiNO₃ → Pb(NO₃)₄ + 2Li₂SO₄
Now we will compare the moles of lithium sulfate with lead sulfate and lithium nitrate.
Pb(SO₄)₂ : Li₂SO₄
1 : 2
2.25 : 2/1×2.25 = 4.5 mol
LiNO₃ : Li₂SO₄
4 : 2
9.62 : 2/4×9.62 = 4.81 mol
Pb(SO₄)₂ produces less number of moles of Li₂SO₄ thus it will act as limiting reactant and limit the yield of Li₂SO₄.
Number 2 lower entropy and higher entropy
Answer: a) 
: negative
b) 
: positive
c) 
: positive.
d) 
: negative
e) 
: positive.
f) 
: positive.
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 is said to decrease and vice versa.
is positive when randomness increases and is negative when randomness decreases.
a)
As ions are moving to solid form , randomness decreases and thus sign of is negative.
b)
As solid is changing to gas, randomness increases and thus sign of is positive.
c)
As 2 moles of reactants are converted to 4 moles of products , randomness increases and thus sign of is positive.
d)
As gas is changing to solid, randomness decreases and thus sign of is negative.
e)
As 7 moles of reactants are converted to 8 moles of products , randomness increases and thus sign of is positive.
f)
As solid is changing to gas, randomness increases and thus sign of is positive.
