Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
In this item, we are simply to find the ions that may bond and are able to form a formula unit. We are also instructed to give out their name. There are numerous possible combinations of ions to form a compound. Some answers are given in the list below.
1. Na⁺ , Cl⁻ , NaCl ---> sodium chloride (this is most commonly known as table salt)
2. C⁴⁺ , O²⁻ , CO₂ ---> carbon dioxide
3. Al³+ , Cl⁻ , AlCl₃ ----> aluminum chloride
4. Ca²⁺ , Cl⁻ , CaCl₂ ---> calcium chloride
5. Li⁺ , Br⁻ , LiBr ---> lithium bromide
6. Mg³⁺ , O²⁻ , Mg₂O₃ ----> magnesium oxide
7. K⁺ , I⁻ , KI ---> potassium iodide
8. H⁺ , Cl⁻ , HCl --> hydrogen chloride
9. H⁺ , Br⁻ , HBr ----> hydrogen bromide
10. Na⁺ , Br⁻ , NaBr ---> sodium bromide
Answer:
[N₂] = 0.032 M
[O₂] = 0.0086 M
Explanation:
Ideal Gas Law → P . V = n . R . T
We assume that the mixture of air occupies a volume of 1 L
78% N₂ → Mole fraction of N₂ = 0.78
21% O₂ → Mole fraction of O₂ = 0.21
1% another gases → Mole fraction of another gases = 0.01
In a mixture, the total pressure of the system refers to total moles of the mixture
1 atm . 1L = n . 0.082L.atm/mol.K . 298K
n = 1 L.atm / 0.082L.atm/mol.K . 298K → 0.0409 moles
We apply the mole fraction to determine the moles
N₂ moles / Total moles = 0.78 → 0.78 . 0.0409 mol = 0.032 moles N₂
O₂ moles / Total moles = 0.21 → 0.21 . 0.0409 mol = 0.0086 moles O₂
Answer:
2 only is a pretty accurate answer the others dont make sense to me.
Explanation:
