<span>Answer: 100 ml
</span>
<span>Explanation:
1) Convert 1.38 g of Fe₂S₃ into number of moles, n
</span>i) Formula: n = mass in grass / molar mass
<span>
ii) molar mass of </span><span>Fe₂S₃ =2 x 55.8 g/mol + 3 x 32.1 g/mol = 207.9 g/mol
</span>
iii) n = 1.38 g / 207.9 g/mol = 0.00664 moles of <span>Fe₂S₃
</span>
<span>2) Use the percent yield to calculate the theoretical amount:
</span>
<span>65% = 0.65 = actual yield/ theoretical yield =>
</span>theoretical yield = actual yield / 0.65 = 0.00664 moles / 0.65 = 0.010 mol <span>Fe₂S₃</span><span>
3) Chemical equation:
</span>
<span> 3 Na₂S(aq) + 2 FeCl₃(aq) → Fe₂S₃(s) + 6 NaCl(aq)
4) Stoichiometrical mole ratios:
</span>
<span>3 mol Na₂S : 2 mol FeCl₃ : 1 mol Fe₂S₃ : 6 mol NaCl
5) Proportionality:
</span>2moles FeCl₃ / 1 mol Fe₂S₃ = x / 0.010 mol Fe₂S₃
<span>
=> x = 0.020 mol FeCl₃
6) convert 0.020 mol to volume
</span>
<span>i) Molarity formula: M = n / V
</span>
<span>ii) V = n / M = 0.020 mol / 0.2 M = 0.1 liter = 100 ml
</span>
Here try this presentation, it should help :)
https://prezi.com/6ofdo3fadl9a/exothermic-and-endothermic-reactions-in-everyday-life/
Answer:
i think its B but im not so sure
Answer:
False
Explanation:
While chemical reactions can proceed in the forward direction , they can in fact also proceed in the backward direction too. The direction they would proceed depends majorly on the state of chemical equilibrium at that particular time for that particular chemical reaction.
It should be known that when a chemical reaction proceeds in the forward way, more products are formed and the reactants are used up. If however, the chemical reaction proceed in the backward way, more reactants are formed and the products are used up.
A practical example is in the case of an exothermic reaction. This is one in which heat is released to the surroundings as a result of the reactants being at a higer energy level compared to the product. Now, depending on the prevailing equilibrium constraint, the reaction could proceed forward or backward.
If for example, the temperature is decreased, this is a constraint being applied to the equilibrium state. The chemical reaction would take a shift and will favor the forward reaction and more of the products will be formed. And also of the temperature is increased, it is the backward reaction that is favored
