The initial concentration of the unknown acid is 0.1900 M.
Explanation:
Titration is a chemical method of analysis to know the concentration and volume of the unknown chemical or analyte.
The formula for the titration is:
Macid x Vacid = Mbase x V base
The volume must be in litres. The volume is given in ml it should be divided with 1000 to obtain values in litre.
Data given are:
volume of acid= 10 ml 0.01 L
Molarity of the acid = ?
volume of the NaOH or base = 15.4 ml or 0.0154 L (equivalence point of the base)
molarity of the base = 0.1234 M
Applying the formula and putting the values, we get
Macid x 0.01 = 0.1234 x 0.0154
Macid = 0.1900 M
The weak acid is having molarity of 0.1900 M against the strong base with molarity of 0.1234M.
Distillation :)
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Correct Question:
A chemist measures the enthalpy change ΔH during the following reaction: Fe(s) + 2HCl(g)-->FeCl2(s) + H2 ΔH=-157.0 kJ. Use this information to complete the table below. Round each of your answers to the nearest kJ/mol
Answer:
-314 kJ
+628 kJ
+157 kJ
Explanation:
The enthalpy change of a reaction measures the amount of heat that is lost or gained by it. If ΔH >0 the heat is gained, and the reaction is called endothermic, if ΔH<0, the heat is lost, and the reaction is called exothermic.
If the reaction is inverted, the value of ΔH is inverted too (the opposite endothermic reaction is exothermic), and if the reaction is multiplied by a constant, ΔH will be multiplied by it too.
1) 2Fe(s) + 4HCl --> 2FeCl2(s) + 2H2(g)
This reaction is the product of the given reaction by 2, so
ΔH = 2*(-157) = -314 kJ
2) 4FeCl2(s) + 4H2(g) --> 4Fe(s) + 8HCl(g)
This reaction is the inverted reaction given multiplied by 4, so
ΔH = 4*(157) = +628 kJ
3) FeCl2(s) + H2(g) --> Fe(s) + 2HCl
This reaction is the inverted reaction given, so
ΔH = +157 kJ
Answer:
Explanation:
Hello,
In this case, for this heat transfer process in which the heat lost by the hot platinum is gained by the cold deuterium oxide based on the equation:
We can represent the heats in terms of mass, heat capacities and temperatures:
Thus, we solve for the mass of platinum:
Next, by using the density of platinum we compute the volume:
Which computed in terms of the edge length is:
Therefore, the edge length turns out:
![a=\sqrt[3]{180cm^3}\\ \\a=5.65cm](https://tex.z-dn.net/?f=a%3D%5Csqrt%5B3%5D%7B180cm%5E3%7D%5C%5C%20%5C%5Ca%3D5.65cm)
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