Given :
Temperature, T = 55° C = ( 55 + 273 ) K = 328 K .
Volume of container, V = 28.9 dm³ = 0.0289 m³ .
Pressure, P = 144 kPa = 144000 Pa .
To Find :
Number of moles of nitrogen gas.
Solution :
We know, by ideal gas equation :
PV = nRT ( R ( universal gas constant ) = 8.31 J K⁻¹ mol⁻¹ .
Therefore, number of moles of nitrogen gas is 1.53 moles.
Answer:
The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.
Explanation:
Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.
Answer : Gaseous water molecules condense when they cooled. Liquid water molecules evaporate when they heated.
Explanation :
Condensation : It is a process in which a phase changes from gaseous state to liquid state. This process occurs when the water molecules in the air cool down and they join together to form liquid water.
Evaporation : It is a process in which a phase changes from liquid state to gaseous state. This process occurs when the water is heated, the molecules in the water move and vibrate quickly that they escape into the atmosphere as water vapor.
