Answer:
She could prove that it is a combination of substances by looking for a change in color, or the formation of bubbles. She could also try to pull the combination apart by physical means alone.
Explanation:
Given parameters:
Initial volume = 120ml
Initial temperature = 35°C
Initial pressure = 1.2bar
Final volume = 180ml
Final temperature = 35°C
Unknown:
Final pressure = ?
To solve this problem, we apply the combined gas law. The expression is given below;

Where P₁ is the initial pressure
P₂ is the final pressure
V₁ is the initial volume
V₂ is the final volume
T₁ is the initial temperature
T₂ is the final temperature
We need to convert the parameters to standard units
take the volume to dm³;
1000ml = 1dm³
120ml =
dm³ = 0.12dm³ = initial volume
Final volume;
1000ml = 1dm³
180ml =
dm³ = 0.18dm³
Now, the temperature;
K = 273 + °C
Initial temperature = 273 + 35 = 308k
Final temperature = 308k
We then input the parameters into the equation;
Solving for P₂;
P₂ = 0.8bar
The new pressure or final pressure in the vessel is 0.8bar
The mass of iron block is 500 g. The amount of energy required to melt the iron block needs to be calculated. Melting means conversion of solid to liquid thus, heat of fusion is used which is 247 J/g.
From heat of fusion, 247 J of energy is released by melting 1 g of iron block. Thus, the amount of heat released by melting 500 g of iron rod will be:
H= 247 J/g× 500 g=1.23×10^{5}
Hence, option B is correct.
Answer: Gas
Explanation: Because to check temperature of a room you use a gas in then room