N2 + 3H2 ---> 2NH3
nitrogen + hydrogen ---> ammonia
<span>atomic weights: Al = 26.98, Cl = 35.45
In this reaction; 2Al = 53.96 and 3Cl2 = 212.7
Ratio of Al:Cl = 53.96/212.7 = 0.2537 that is approximately four times the mass Cl is needed.
Step 2:
(a) Ratio of Al:Cl = 2.70/4.05 = 0.6667
since the ratio is greater than 0.2537 the divisor which is Cl is not big enough to give a smaller ratio equal to 0.2537.
so Cl is limiting
(b)since Cl is the limiting reactant 4.05g will be used to determine the mass of AlCl3 that can be produced.
From Step 1:
212.7g of Cl will produce 266.66g AlCl3
212.7g = 266.66g
4.05g = x
x = 5.08g of AlCl3 can be produced
(c)
Al:Cl = 0.2537
Al:Cl = Al:4.05 = 0.2537
mass of Al used in reaction = 4.05 x 0.2537 = 1.027g
Excess reactant = 2.70 - 1.027 = 1.67g
King Leo · 9 years ago</span>
Answer:
a. The reaction is endothermic.
Explanation:
The heat involved in a chemical reaction is given by the enthalpy change (ΔH), which is equal to the balance between the chemical bonds that are broken (release energy) and the chemical bonds that are formed (need energy):
ΔH ≅ bonds broken - bonds formed
If broken bonds > bonds formed ⇒ ΔH > 0 ⇒ endothermic reaction
Therefore, the reaction is endothermic (it requires energy).
To test if the hypothesis is correct, a good way is to think of it this way:
Density = mass/volume, right?
Calculate the mass and volume of each and do the equation; this will test your hypothesis.
You will be left with the density of each. But, make sure that the sample sizes are the same (controlled variable) otherwise it will be an unfair test.
