This is stoichiometry question which involves unit conversions.
Given values:
CaO mass = 11.2g
NH4Cl mass = 22.4g
First convert the two given values to moles.
(11.2g CaO)(1mol CaO / 56.08g CaO) = 0.20mol CaO
(22.4g NH4Cl)(1mol NH4Cl / 53.49g NH4Cl) = 0.42mol NH4Cl
CaO reacts with NH4Cl on a 1:2 ratio. This means that the reactants will react in this ratio: 0.20mol CaO: 0.40mol NH4Cl. There will be an excess of 0.02mol NH4Cl unreacted because CaO is the limiting reagent (CaO is used up completely in the reaction and excess NH4Cl remains unreacted).
Now given the equation:
CaO(s) + 2 NH4Cl(s) = 2 NH3(g) + H2O(g) + CaCl2(s)
It is seen that every 2mol of NH4Cl reacts to form 2mol of NH3 because all the elements in the composition of NH3 is found in NH4Cl. This means that NH4Cl and NH3 are on a 1:1 reaction ratio. Now we use this relationship:
0.40mol NH4Cl reacted : 0.40mol NH3 produced. Convert NH3 produced to grams to find solution:
(0.40mol NH3)(17.03g NH3 / 1mol NH3) = 6.8g NH3 produced a)
We determined the excess reactant as 0.02mol NH4Cl in a). Now we convert it to grams:
(0.02mol NH4Cl)(53.49g NH4Cl / 1mol NH4Cl) = 1.07g NH4Cl unreacted b)
Hope this helps
U can ask any doubt if u have
The volume becomes two. You have to use the equation P1 x V1 = P2 x V2
P is pressure and V is volume.
P1 = 50 P2 = 125
V1 = 5 V2 = v (we don't know what it is)
Then set up the equation:
50 times 5 = 125 times v
250 = 125v
the divide both sides by 125 and isolate v
2 = v
Therefore the volume is decreased to 2.
Also, Boyle's Law explains this too: Volume and pressure are inversely related, This means that when one goes up the other goes down (ie when pressure increases volume decreases and vice versa). Becuase the pressure went up from 50 KPa tp 125 KPa the volume had to decrease.
Answer: Anna stated that ionic compounds have high melting point and low boiling point. The error in the statement is that ionic compound have low boiling point, instead ionic compounds have high boiling point, because in an ionic compound, the force of attraction working between two ions is very strong and hence the bonds present are very strong, and a lot of energy is needed to break them
