The answer is C , hope I helped
Nails are made up of iron not of phosphorus and barium.
As both phosphorous and barium are relatively weaker than iron ,phosphorus breaks easily and barium is also fairly weak. Iron nails are already also not that strong, but their weight and strength are sufficient.
So the nails are made up of iron.
HCI is one of the most common acids out of the following
The easiest way is to use the Law of Gay-Lussac. This law states that there is a direct relation between the temperature in Kelvin of a gas and the pressure.
Then, namig p the pressure and T the temperature in Kelvin and using subscripts for every state:
p/T is constant ==> p_1 / T_1 = p_2/T_2
From which you obtain:
p_2 = [p_1 / T_1] * T_2
T_1 = 33.0 + 273.15 = 306.15 K
T _2 = 21.4 + 273.15 = 294.55 K
p_1 = 1014 kPa
p_2 = 1014 kPa * 294.55 K / 306.15 K = 975.6 kPa
