In chemistry, there is a common note that says, "Like dissolves like".
This pertains to the concept that polar substances can dissolve only other polar substances. Also, nonpolar substances are also only able to dissolve nonpolar substances.
Polarity of the substance depends primarily on the type of bond and the difference in electronegativity.
Water is a polar substance while vegetable oil is not. From the concept presented above, it may be concluded that water will not be able to dissolve the vegetable oil and the assumption is logical.
First determine the formal oxidation numbers:
N changes from +2 to +5 going from NO to (NO3)- O remains -2 the whole time Cr changes from +6 to +3
Now write the half reactions, balance the oxygens with the required number of waters and then balance the hydrogens with the required number of protons:
Oxidation half reaction:
NO(aq) + 2 H2O(l) ---> (NO3)-(aq) + 4 H+(aq) + 3 e-
Reduction half reaction:
(Cr2O7)2-(aq) + 14 H+(aq) + 6 e- ---> 2 Cr3+(aq) + 7 H2O(l)
Now balance the number of electrons on both sides and add them together:
2 NO(aq) + 4 H2O(l) ---> 2 (NO3)-(aq) + 8 H+(aq) + 6 e- (Cr2O7)2-(aq) + 14 H+(aq) + 6 e- ---> 2 Cr3+(aq) + 7 H2O(l) --------------------------------------... 2 NO(aq) + (Cr2O7)2-(aq) + 6 H+(aq) ---> 2 (NO3)-(aq) + 2 Cr3+(aq) + 3 H2O(l)
Notice that the charge is the same in both sides, which is an indication that the redox equation has been balanced correctly:
-2 + 6 = -2 + 2(+3) +4 = +4
Answer:
ΔU = - 168 KJ
Explanation:
- ΔU = Q + W.....................first law
∴ W = - 61 KJ........A system performs on its surroundings
∴ Q = - 107 KJ,,,,,,A system release heat
⇒ ΔU = - 107 KJ - 61 KJ = - 168 KJ
Answer:
To make one gallon of 5% methyl alcohol we require 115.2oz of water and 12.8oz of 50% methyl alcohol solution
Explanation:
Required solution = 1 gallon of 5% methyl alcohol or1 gallon 5/100 moles per dm3 of methyl alcohol
Number of moles in required solution = 0.05moles/dm3 × 1gallon
Where 1 gallon = 0.00378dm3
= 0.05moles/dm3 × 0.00378dm3 = 1.892×10-4 moles
The quantity of the 50% solution with Paul required is given by
50% = 50/100 = 0.5 moles/dm3
Volume of 50% solution of methyl alcohol that contains 1.892×10-4 moles
= concentration = (Number of moles)/(volume of dm3) of solution thus
Volume of solution = (Number of moles)/(concentration)
1.892/0.5 =3.785×10-4dm3 of the 50% solution is required to make 1 gallon of 5% solution
3.785×10-4dm3 = 12.8oz
Thus to make 1 gallon or 128oz solution of 5% alcohol requires
128oz - 12.8 oz = 115.2oz of water and 12.8oz of 50% methyl alcohol solution
Answer:
A
Explanation:
I think it's pressure. Using the process of elimination, sediment is the matter that's on the bottom of a liquid or solution, deposition is the process of deposing, eruption is the process of erupting, and pressure's formula is force/area, so pressure is the answer.