Because size of an atom INCREASES from top to bottom and DECREASES from left to right on the periodic table. If to elements are in the same period they can't increase in size based on the up or down trend. Instead, notice that Alkali Metals are LEFT of Alkaline Earth Metals. Therefore, the Alkali Metal will be larger than the Alkaline Earth Metals.
Water=h20
=2.0*10^22 molecules
Answer:
368.92g
Explanation:
Firstly, let's balance the equation which is
2NO + O₂ ---> 2NO₂
Starting with 8.02 mol of NO let's calculate the moles of oxygen which is in a 2 : 1 molar ratio
2NO + O₂
2 : 1
8.02 mol : x mol
Moles of O₂ = 8.02 ÷ 2 = 4.01 mol
Doing the same thing for 18.75 mol of O₂ to calculate the number of moles of NO
2NO + O₂
2 : 1
x mol : 18.75 mol
Moles of NO = 18.75 × 2 = 37.5 however we are told we have 8.02 moles of NO, so we are unable to use 18.75 mol of O₂
Using 8.02 mol of NO to figure out the number of moles of NO₂ :
2NO : 2NO₂
They have the same molar ratio of 2 : 2, so the number of moles is 8.02
Using formula moles = mass / Molar mass
Rearranging to find mass = moles × molar mass
Molar mass of NO₂ = 14 + 16 + 16 = 46
Mass = 46 × 8.02 = 368.92g
