An alpha particle is identical to a helium atom that has been stripped of its two electrons
Answer:
Percent yield = 69.4%
Explanation:
Given data:
Percent yield = ?
Actual yield of copper = 4.65 g
Mass of aluminium = 1.87 g
Mass of copper sulfate = excess
Solution:
Chemical equation:
2Al + 3CuSO₄ → Al₂(SO₄)₃ + 3Cu
Number of moles of Aluminium:
Number of moles = mass/ molar mass
Number of moles = 1.87 g/27 g/mol
Number of moles = 0.07 mol
Now we will compare the moles of Al with copper.
Al : Cu
2 : 3
0.07 : 3/2×0.07 =0.105 mol
Mass of Copper:(Theoretical yield)
Mass = Number of moles × molar mass
Mass = 0.105 mol × 63.5 g/mol
Mass = 6.7 g
Percent yield:
Percent yield = Actual yield / theoretical yield × 100
Percent yield = 4.65 g/ 6.7 g × 100
Percent yield = 69.4%
Answer:
The attached figure shows the structure of dimethyl terephthalate.
Explanation:
Dimethyl terephthalate is a compound whose formula is C6H4 (COOCH3) 2. It is a diester produced from terephthalic acid and methanol. It is characterized by being a white solid. Another method for the preparation is from p-xylene and methanol, which is characterized by having an oxidation and an esterification.
Answer:
it is the primary electricity in solid. they also make up an atom.
Explanation:
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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
