As i am reading the problem, i notice they give two concentrations (M), a volume and asking for the other volume; this should be a hint that we need to use the dilution formula---> M1V1 = M2V2
M1= 2.55 M
V1= ?
M2= 0.75 M
V2= 125 mL
now, we plug in the values into the formula
(2.55 x V1) = (0.75 x 125)
V1= 36.8 mL
It means the system absorbs energy from surrounding objects; usually, but not always, involving heat
Answer:
.
Explanation:
Consider the oxidation state on each of the element:
Left-hand side:
- O: -2 (as in most compounds);
- Cr: ;
- Fe: +2 (from the charge of the ion);
Right-hand side:
Change in oxidation state:
- Each Cr atom: decreases by 3 (reduction).
- Each Fe atom: increases by 1 (oxidation).
Changes in oxidation states shall balance each other in redox reactions. Thus, for each Cr atom on the left-hand side, there need to be three Fe atoms.
Assume that the coefficient of the most complex species is 1. There will be two Cr atoms and hence six Fe atoms on the left-hand side. Additionally, there are going to be seven O atoms.
Atoms are conserved in chemical reactions. As a result, the right-hand side of this equation will contain
- two Cr atoms,
- six Fe atoms, and
- seven O atoms.
O atoms seldom appear among the products in acidic environments; they rapidly combine with ions to produce water . Seven O atoms will make seven water molecules. That's fourteen H atoms and hence fourteen ions on the product side of this equation. Hence the balanced equation. Double check to ensure that the charges on the ions also balance.
.
Answer:
A) and D)
Explanation:
I just completed this assignment and these are the correct options!
1) If we had excess Cl2, then limiting reagent is Al
so moles of Al will be the same as the moles of AlCl3 produced at the output
moles of Al = 23/27 = 0.8518 moles
2)If we had excess Al , then limiting reagent is Cl2
so moles of Cl2 will be the 3/2 times as the moles of AlCl3 produced at the output
moles of Cl2 = 28/71 = 0.394 moles
<span>hence moles of AlCl3 = 0.394*2/3 = 0.2629 moles</span>