Answer:
8.34
Explanation:
1) how much moles of NH₃ are in the reaction;
2) how much moles of H₂ are in the reaction;
3) the required mass of the H₂.
all the details are in the attachment; the answer is marked with red colour.
Note1: M(NH₃) - molar mass of the NH₃, constant; M(H₂) - the molar mass of the H₂, constant; ν(NH₃) - quantity of NH₃; ν(H₂) - quantity of H₂.
Note2: the suggested solution is not the shortest one.
I am almost positive that the answer is D
The Boyle-Mariotte's law or Boyle's law is one of the laws of gases that <u>relates the volume (V) and pressure (P) of a certain amount of gas maintained at constant temperature</u>, as follows:
PV = k
where k is a constant.
We can relate the state of a gas at a specific pressure and volume to another state in which the same gas is at different P and V since the product of both variables is equal to a constant, according to the Boyle's law, which will be the same regardless of the state of the gas. In this way,
P₁V₁ = P₂V₂
Where P₁ and V₁ is the pressure and volume of the gas to a state 1 and P₂ and V₂ is the pressure and volume of the same gas in a state 2.
In this case, in the state 1 the gas occupies a volume V₁ = 100 mL at a pressure of P₁ = 150 kPa. Then, in the state 2 the gas occupies a volume V₂ (that we must calculate through the boyle's law) at a pressure of P₂ = 200 kPa. Substituting these values in the previous equation and clearing V₂, we have,
P₁V₁ = P₂V₂ → V₂ =
→ V₂ = 
→ V₂ = 75 mL
Then, the volume occupied by the gas at 200 kPa is V₂ = 75 mL
Answer:
Copper>Steel>Aluminium
Explanation:
Hello,
Since the heat capacity accounts for the required heat to increase by 1°C, 1 kg of the metal, copper is the one that has the lower heat capacity, it means that it requires the least amount of energy to warm up (increase its temperature), this could be substantiated via the mathematical definition of heat capacity:

Solving for
:

It means that the lower the heat capacity, the higher the final temperature.
Best regards.
A, B, C, and D, because they are changing from a solid to a liquid, liquid to solid, and solid to gas. Phase changes are when a solid, liquid, or gas, turns into a solid, liquid, or gas. Ex. Ice melting is a solid changing into a liquid. Hope this helps!