Answer:
B
Explanation:
Entropy can be decreased only in the cases when liquid is converted to solid
Answer:
Hence the<u> ions per mole</u> are:
In one mole of Li2SO3 , the number of the atoms are
Explanation:
The formula of lithium sulfite is Li2SO3.
It contain Li+ and SO3(2-) ions.This can be represented by :
Hence one mole of Li2SO3 will give 2 Li+ ions and 1 SO3 (2-) ion.
Hence the<u> ions per mole</u> are:
Number of atoms in lithium sulfite depends upon the<u> mass of the Li2SO3 present</u> .
Li2SO3 = 93.94 g/mole
This mass is equal to 1 mole of Li2SO3
Now<u> 1 mole</u> of any substance contain Na atoms . This is known as Avogadro Number.
Hence , if 1 mole of Li2SO3 is present then it contains Na atoms
If other then 1 mole present then number of atoms are calculated by:
Here n = number of moles
if the mass of the compound is given then first calculate the number of moles.
a. AlCl₃ ⇒ limiting reactant(smaller ratio)
Cu ⇒ excess reactant
b. the mass of leftover reactant : 7.207 g
<h3>Further explanation</h3>
Given
25 g Cu
25 g AlCl3
Required
a. the excess and limiting reactants
b. the mass of leftover reactant
Solution
Reaction
3Cu + 2AlCl₃ ⇒ 3CuCl₂ + 2Al
mol Cu(Ar = 63.5 g/mol) :
mol = mass : Mw
mol = 25 : 63.5
mol = 0.394
mol AlCl3(MW=133,34 g/mol) :
mol = 25 : 133,34 g/mol
mol = 0.187
mol ratio to reaction coefficient Cu : AlCl₃ =
AlCl₃ ⇒ limiting reactant(smaller ratio)
Cu ⇒ excess reactant
b. the mass of leftover reactant :
mol Cu = 3/2 x 0.187 = 0.2805
mol left = 0.394 - 0.2805 = 0.1135
mass = 0.1135 x 63.5 = 7.207 g