- Endothermic reaction means the reactant side takes heat from surrounding and get decomposed i.e ∆H=-ve
- If the equation is exothermic then it means the reactant is happy to decompose .But it's not as it's endothermic
Now
- HgO is Omitted from our solution option.
Hg is a atom so no bonds hence no bond strength occurs.
- O_2 is a molecule and so it's our answer .
2Ca + O2 = 2CaO
First, determine which is the excess reactant
72.5 g Ca (1 mol) =1.8089725036
(40.078 g)
65 g O2 (1 mol) =2.0313769611
(15.999g × 2)
Since the ratio of to O2 is 2:1 in the balanced reaction, divide Ca's molar mass by 2 to get 0.9044862518. this isn't necessary because Ca is already obviously the limiting reactant. therefore, O2 is the excess reactant.
Now do the stoichiometry
72.5 g Ca (1 mol Ca) (1 mol O2)
(40.078 g Ca)(2 mol Ca)(31.998g O2)
=0.0282669621 g of O2 left over
PH= -log [H+]
= - (log 0.034)
= - (-1.5)
= 1.5
We are given with a compound, Zinc (Zn) having a 1.7 x 10
^23 atoms. We are tasked to solve for it's corresponding mass in g. We need to
find first the molecular weight of Zinc, that is
Zn= 65.38 g/mol
Not that 1 mol=6.022x10^{23} atoms, hence,
1.7 x 10 ^23 atoms x 1 mol/6.022x10^{23} atoms x65.38
g/ 1mol
=18.456 g of Zn
Therefore, the mass of Zinc 18.456 g
