The Bohr model proposed that electrons could just have characterized vitality levels thus when rotting back to a lower vitality level discharge a specific measure of vitality. Since the measure of vitality could be changed over to a specific recurrence then particular emanation lines were found in the electromagnetic range. Alternate speculations couldn't clarify the discharge lines.
Answer: Option (d) is the correct answer.
Explanation:
Since the given formula is 
. According to cross method formula, magnesium has +2 charge so, 
is multiplied by 2.
Thus, 1 molecule of magnesium phosphate will contain 2 atoms of phosphorus.
Therefore, three molecules of magnesium phosphate contains following number of atoms.
Hence, we can conclude that there are 6 atoms of phosphorus in three molecules of magnesium phosphate, .
Answer:
???
Explanation:
i would help answer but your post has no diagrams or at least there not showing up
Molality is the number of moles of solutes in 1 kg of solvent.
the molality of solution to be prepared is 2.0 molal.
therefore 2 moles in 1 kg water.
the mass of Li₂S required is - 46 g/mol x 2.0 mol = 92 g
the mass in 1 kg of solvent is - 92 g
Therefore mass of Li₂S required in 1600.0 g is - 92 g/kg x 1.6 kg = 147.2 g
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
