<span>ideal gas law: PV = nRT so .....</span><span> V = PV/(RT) </span> <span> Initial number of moles of Cl, n = 0.943*5.11/(0.08206 × 286) mol = 0.2053 moles. </span><span> We know the molar mass of K (potassium) = 39.0 g/mol </span> <span>sooo.... The Initial number of moles of K = 29.0 g/(39.0 g/mol) = 0.7436 moles</span>
<span>Find the balanced equation for the reaction : </span><span>2K + Cl2 → 2KCl </span> <span>Mole ratio of K:Cl = 2:1 </span>
<span>So after the reaction, the amount of K needed = (0.2053 mol) × 2 = 0.4106 mol which is less than 0.7436 mol </span> <span> This means that K is in excess but Cl completely reacts. </span>
<span> So we know the mole ratio is Cl:KCl = 1 : 2 </span> <span>Number of moles of Cl (completely) reacted = 0.2053 mol which means the n</span><span>umber of moles of KCl formed = (0.2053 mol) × 2 = 0.4106 mol </span>
<span>Molar mass of KCl = (39.0 + 35.5) g/mol = 74.5 g/mol </span> <span>Mass of KCl formed = 0.4106 mol * 74.5 g/mol = 30.6 g</span>
The least energetic line of Hydrogen atom lies in <em>Brackett Series </em>when n = 4 because these are least energetic, have longer wavelengths and lies in Infrared region of spectrum. No traces of <em>Pfund series </em>are formed by H=atoms.