Answer:
Electron dot diagram is attached below
Explanation:
Sodium is alkali metal and present in group one. It has one valence electron. All alkali metal form salt when react with halogens.
Sodium loses its one electron to get stable. While all halogens have seven valence electrons they need only one electron to get stable electronic configuration.
When alkali metals such as sodium react with halogen fluorine it loses its one valence electron which is accepted by fluorine and ionic bond is formed. The compound formed is called sodium fluoride.
Na + F → NaF
In cross and dot diagram electrons of one atom are shown as dots while other atom shown as cross to distinguish.
Electron dot diagram is attached below.
Answer:
429.4 kJ are absorbed in the endothermic reaction.
Explanation:
The balanced chemical equation tells us that 1168 kJ of heat are absorbed in the reaction when 4 mol of NH₃ (g) react with 5 mol O₂ (g).
So what we need is to calculates how many moles represent 25 g NH₃(g) and calculate the heat absorbed. (NH₃ is the limiting reagent)
Molar Mass NH₃ = 17.03 g/mol
mol NH₃ = 25.00 g/ 17.03 g/mol = 1.47 mol
1168 kJ /4 mol NH₃ x 1.47 mol NH₃ = 429.4 kJ
True ^^ they explained it well
