Answer:
[KCl] = 1.2 M
Explanation:
We need to complete the reaction:
2KCl(aq) + Pb(NO₃)₂(aq) → 2KNO₃(aq) + PbCl₂(s)↓
By stoichiomety we know that 1 mol of chloride needs 1 mol of nitrate to react:
Let's find out the moles of nitrate, we have:
Molarity = mol/volume(L)
We convert the volume → 30 mL . 1L/1000mL = 0.030L
Molarity . volume(L) = moles → 0.400 M . 0.030L = 0.012 moles
Therefore, we can make a rule of three.
1 mol of nitrate reacts with 2 moles of chloride
Then, 0.012 moles of nitrate must react with (0.012 . 2) / 1 = 0.024 moles of KCl
We convert the volume from mL to L → 20 mL . 1L /1000mL = 0.020L
Molarity = mol /volume(L) → 0.024 mol /0.020L = 1.2 M
The reaction uses B) 9.0 g Br₂.
iron + bromine ⟶ product
2.0 g + <em>x</em> g ⟶ 11.0 g
According to the <em>Law of Conservation of Mass</em>, the total mass of the reactants must equal the total mass of the products.
∴2.0 + <em>x</em> = 11.0
<em>x</em> = 11.0 – 2.0 = 9.0
The reaction uses 9.0 g Br₂.
Answer:
A. N₂(g) + 3H₂(g) -----> 2NH₃ exothermic
B. S(g) + O₂(g) --------> SO₂(g) exothermic
C. 2H₂O(g) --------> 2H₂(g) + O₂(g) endothermic
D. 2F(g) ---------> F₂(g) exothermic
Explanation:
The question says predict not calculate. So you have to use your chemistry knowledge, experience and intuition.
A. N₂(g) + 3H₂(g) -----> 2NH₃ is exothermic because the Haber process gives out energy
B. S(g) + O₂(g) --------> SO₂(g) is exothermic because it is a combustion. The majority, if not all, combustion give out energy.
C. 2H₂O(g) --------> 2H₂(g) + O₂(g) is endothermic because it is the reverse reaction of the combustion of hydrogen. If the reverse reaction is exothermic then the forward reaction is endothermic
D. 2F(g) ---------> F₂(g) is exothermic because the backward reaction is endothermic. Atomisation is always an endothermic reaction so the forward reaction is exothermic
Answer:
he is a weelder because of him taking a peice of metal and recreateing it.
Explanation:
