Respuesta :
Answer: 185.66 grams of Lithium chloride must decompose.
Explanation:
To calculate the moles, we use the following equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Moles of Lithium:
Given mass of lithium = 30.3 grams
Molar mass of lithium = 6.91 g/mol
Putting values in above equation, we get:
[tex]\text{Number of moles}=\frac{30.3g}{6.91g/mol}=4.38moles[/tex]
For the given chemical reaction, the equation follows:
[tex]2LiCl\rightarrow 2Li+Cl_2[/tex]
By Stoichiometry of the reaction:
2 moles of lithium metal are produced by 2 moles of lithium chloride
So, 4.38 moles of lithium metal are produced by = [tex]\frac{2}{2}\times 4.38=4.38moles[/tex] of lithium chloride.
Now, to calculate the mass of lithium chloride, we use the moles equation:
Molar mass of lithium chloride = 42.39 g/mol
Putting values in above equation, we get:
[tex]4.38mol=\frac{\text{Given mass}}{42.39g/mol}[/tex]
Mass of lithium chloride = 185.66 grams
Hence, Mass of lithium chloride decomposed is 185.66 grams.
Answer:
185.05 g.
Explanation:
- Firstly, It is considered as a stichiometry problem.
- From the balanced equation: 2LiCl → 2Li + Cl₂
- It is clear that the stichiometry shows that 2.0 moles of LiCl is decomposed to give 2.0 moles of Li metal and 1.0 moles of Cl₂, which means that the molar ratio of LiCl : Li is (1.0 : 1.0) ratio.
- We must convert the grams of Li metal (30.3 g) to moles (n = mass/atomic mass), atomic mass of Li = 6.941 g/mole.
- n = (30.3 g) / (6.941 g/mole) = 4.365 moles.
- Now, we can get the number of moles of LiCl that is needed to produce 4.365 moles of Li metal.
- Using cross multiplication:
- 2.0 moles of LiCl → 2.0 moles of Li, from the stichiometry of the balanced equation.
- ??? moles of LiCl → 4.365 moles of Li.
- The number of moles of LiCl that will produce 4.365 moles of Li (30.3 g) is (2.0 x 4.365 / 2.0) = 4.365 moles.
- Finally, we should convert the number of moles of LiCl into grams (n = mass/molar mass).
- Molar mass of LiCl = 42.394 g/mole.
- mass = n x molar mass = (4.365 x 42.394) = 185.05 g.
