What is a tester? pls answerrr
1 answer:
You might be interested in
Answer:
(a) Homogeneous. 4.7 g of MgCl₂.
(b) 9.1 g
Explanation:
(a)
At 200°C, we can dissolve 54.6g of MgCl₂ in 100 g of water. The mass that we could dissolve in 38.2 g of water is:
Since we can dissolve up to 20.9 g of MgCl₂ and we added only 16.2 g, the mixture is homogeneous and we could add 20.9 g -16.2 g = 4.7 g of solute to make it saturated.
(b)
At 800°C, we can dissolve 66.1 g of MgCl₂ in 100 g of water. The mass that we could dissolve in 38.2 g of water is:
Since we can dissolve up to 25.3 g of MgCl₂ and we added only 16.2 g, we could add 25.3 g - 16.2 g = 9.1 g of solute to make it saturated.
Answer : The enthalpy change of reaction is -23.9 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given final reaction is,
The intermediate balanced chemical reaction will be,
(1)
(2)
First we will reverse the reaction 1 and multiply equation 2 by 3 then adding both the equation, we get :
(1)
(2)
The expression for final enthalpy is,
Therefore, the enthalpy change of reaction is -23.9 kJ