Pv=nRT
where,p=199, R(constant)=8.314, V=4.67 T=30C=293K
n=pv/RT=0.38 moles
It’s chlorine (Cl) having the atomic number 17
A. Fe2O3 + 3CO= 2Fe+3CO2
Here element oxidised is CO or Carbon Monoxide, since oxygen is added.
B. 2HCl+2KMnO4+3H2C2O4=6CO2+2MnO2+2KCl+4H2O
Here Element reduced is 3H2C2O4, since Hydrogen is being added. Also KMnO4 is reduced, since Oxygen is removed.
It's a chemical reaction because when two certain substances are mixed together, a reaction can occur where the molecular structure of the two materials are rearranged to create and entirely different substance.
Within each group of metals, reactivity increases as you go down the group. The valence electrons are less tightly bound and easier to remove, because they are farther away from the nucleus of the atom. A nonmetal tends to attract additional valence electrons to attain a full valence shell.