Answer:
-455 kJ
Explanation:
Let's consider the following thermochemical equation.
4 NH₃(g) + 5 O₂(g) → 4 NO(g) + 6 H₂O(g) ΔH = -1170 kJ
1170 kJ of heat are released per 4 moles of NH₃. Considering that the molar mass of NH₃ is 17.03 g/mol, the amount of heat given of by 26.5 g of NH₃ is:
1 gram = 1000 mg
=>
1 mg = 1/1000 g
25 mg = 25* (1/1000) g = 25/1000 g = 0.025g
A nonmetal requires more energy that a metal to lose an electron.
Transfer of electrons from one species to another species is called a redox reaction. it consists of one species that will give out electrons called an oxidation reaction and the other species take in electrons called reduction reactions. both these half equations together make up a redox reaction.
In oxidation, the oxidation state increases of the species that is oxidised.
In reduction, oxidation state of the species decreases of the species that is reduced.
1)
2AgNO₃(aq) + Cu(s) → Cu(NO₃)₂<span>(aq) + 2Ag(s)
single displacement reaction
oxidation number of Ag </span>decreases from +1 to 0 - reduction reaction
oxidation number of Cu increases from 0 to +2 - oxidation
since both oxidation and reduction reactions take place its a redox reaction.
2)
BaCl₂(aq) + Na₂CrO₄(aq) → BaCrO₄<span>(s) + 2NaCl(aq)
its a double displacement reaction and the ions have been exchanged.
Oxidation numbers of the elements do not change therefore this is not a redox reaction.
3)
</span>H₃PO₄(aq) + 3KOH(aq) → 3H₂O(l) + K₃PO₄<span>(aq)
acid base reaction where the oxidation state of the elements remain the same so its not a redox reaction.
4)
</span><span>CaCO</span>₃<span>(s) → CaO(s) + CO</span>₂<span>(g)?
decomposition reaction where the oxidation states remain the same hence not a redox reaction </span>
Answer:
C
Explanation:
A solution is made when solute is dissolved in a solvent. Take a simple scenario for example, a salt solution typically is comprises of a an amount of salt mixed with a certain volume of water. The mixture of both is what makes a salt solution.
In this case, we need to make a solution if sweetened coffee. Prior to now, we know we have a particular coffee which is unsweetened that is has no sugar in it. Now, we are tasked with the responsibility of making a sweetened coffee. Our coffee is without sugar thus will serve as the solvent because it is the carrier medium. The sugar which obviously would dissolve in the solvent to form a solution would be our solute.
Now dissolving it in the unsweetened coffee thus will give us a sweetened coffee solution.