We are given that alcohol is the solute, which leaves whatever is not alcohol as the solvent. 20.0% of the solution’s mass is alcohol, meaning 80.0% of the solutions mass is solvent. We are given its mass as 170 g, so just multiply 0.800*170 g = 136 g.
<h3>
Answer:</h3>
Li₂S(aq)+Pb(NO₃)₂(aq)
→ PbS(s) + LiNO₃(aq)
K2S(aq)+Sn(NO₃)₄(aq→ SnS(s) + KNO₃(aq)
<h3>
Explanation:</h3>
- According to solubility rules, metal sulfides are insoluble except Calcium sulfide(CaS), Magnesium sulfide(MgS), Barium sulfide(BaS), and those of potassium, sodium, and ammonium.
- Therefore, when all the other sulfides are formed during a reaction they form a precipitate that is shown to be in solid-state.
- Precipitates are formed during precipitation reactions when cations and anions combine to form a compound that is insoluble in water.
In our case; In the equations given, some reactions will take place to form a precipitate while others will not occur.
That is;
- Na₂S(aq)+KCl(aq) → No reaction
- Li₂S(aq)+Pb(NO₃)₂(aq) → PbS(s) + LiNO₃(aq)
- Pb(ClO₃)₂(aq)+NaNO₃(aq) → No reaction
- AgNO₃(aq)+KCl(aq) →AgCl(s) + KNO₃(aq)
- K2S(aq)+Sn(NO₃)₄(aq→ SnS(s) + KNO₃(aq)
The first reaction will not occur.
The second equation is a precipitation reaction that forms lead(ii)sulfide which is a black precipitate.
The third reaction will not take place.
The fourth reaction will be a precipitation reaction forming silver chloride precipitate.
The fifth equation is also a precipitation reaction that forms tin(ii) sulfide, SnS which is a black precipitate.
Therefore; the equations that answers our question are;
- Li₂S(aq)+Pb(NO₃)₂(aq) → PbS(s) + LiNO₃(aq)
- K2S(aq)+Sn(NO₃)₄(aq→ SnS(s) + KNO₃(aq)
Answer:
Exothermic reaction
Explanation:
The freezing of n-octane is an exothermic reaction.
An exothermic reaction is a type of reaction in which energy usually in the form of heat is released to the environment. In an exothermic reaction, the reactants are at a higher energy level compared to the product. Hence heat energy is usually released.
Now, freezing is a change in state from the liquid state to the solid state , for example, the turning of water to ice block.
In freezing, energy is released and hence, thus it is an exothermic reaction
Answer:
Q = 7898.38 J = 7.898 KJ
Explanation:
∴ ΔHv H2O = 47 KJ/mol = 47000 J/mol
∴ molar mass H2O = 18.015 g/mol
⇒ ΔHv H2O = (47000 J/mol)*(mol/18.015 g) = 2608.94 J/g
∴ m H2O = 2.73 g
⇒ ΔHv H2O = (2.73 g)(2608.94 J/g) = 7122.406 J
∴ C H2O = 4.18 J/g°C
∴ ΔT = 100 - 32 = 68°C
⇒ Q = (2.73 g)(4.18 J/g°C)(68°C) + 7122.406 J
⇒ Q = 775.975 J + 7122.406 J
⇒ Q = 7898.38 J