Answer:
- m = 1,000/58.5
- b = - 1,000 / 58.5
1) Variables
- molarity: M
- density of the solution: d
- moles of NaCl: n₁
- mass of NaCl: m₁
- molar mass of NaCl: MM₁
- total volume in liters: Vt
- Volume of water in mililiters: V₂
- mass of water: m₂
2) Density of the solution: mass in grams / volume in mililiters
3) Mass of NaCl: m₁
Number of moles = mass in grams / molar mass
⇒ mass in grams = number of moles × molar mass
m₁ = n₁ × MM₁
4) Number of moles of NaCl: n₁
Molarity = number of moles / Volume of solution in liters
M = n₁ / Vt
⇒ n₁ = M × Vt
5) Substitue in the equation of m₁:
m₁ = M × Vt × MM₁
6) Substitute in the equation of density:
d = [M × Vt × MM₁ + m₂] / (1000Vt)
7) Simplify and solve for M
- d = M × Vt × MM₁ / (1000Vt) + m₂/ (1000Vt)
- d = M × MM₁ / (1000) + m₂/ (1000Vt)
Making the simplistic assumption that the dissolved NaCl(s) does not affect the volume of the solvent water means 1000Vt = V₂
- d = M × MM₁ / (1000) + m₂/ V₂
m₂/ V₂ is the density of water: 1.00 g/mL
- d = M × MM₁ / (1000) + 1.00 g/mL
- M × MM₁ / (1000) = d - 1.00 g/mL
- M = [1,000/MM₁] d - 1,000/ MM₁
8) Substituting MM₁ = 58.5 g/mol
- M = [1,000/58.5] d - [1,000/ 58.5]
Comparing with the equation Molarity = m×density + b, you obtain:
- m = 1,000/58.5
- b = - 1,000/58.5
Answer: D, Thermal energy
Explanation: particles in a substance will move for one reason. That reason is heat. The hotter the substance the more the particles will move.
The best and most correct answer among the choices provided by the question is the fourth choice or letter D.
<span>A2+ would represent the ion of an element from Group 2A</span>
I hope my answers has come to your help. God bless and have a nice day ahead!
Answer:
Well, carbon monoxide can be created from formic acid by adding sulphuric acid which will dehydrate said formic acid:
HCOOH
−
→
−
−
−
H
2
SO
4
CO+H
2
O
HCOOH→HX2SOX4CO+HX2O
Therefore, we can imagine the reverse reaction theoretically, which would make carbon monoxide an acidic oxide. However, the forward reaction does not proceed easily and it needs both the high acidity of sulphuric acid and its strong dehydrative properties to actually work. And your question mentions using hot, concentrated sodium hydroxide to make the reverse one work.
Most oxides that are classified as acidic or basic either have a very electrophilic central atom (e.g.
CO
2
COX2
) which can be attacked by the weak nucleophile water (which in turn can then release an acidic proton), or they have a high charge density on the oxygen which allows it to abstract a proton from water directly. Carbon monoxide is neither. If you check out its molecular orbitals, you will notice that even though carbon is partially positive it has the largest HOMO contribution, meaning a proton would be more likely to attatch to the carbon side — which doesn’t want one at all. The LUMO is, luckily, also more carbon-centred, meaning nucleophilic attacks on carbon are possible. However, it is also degenerate due to the double bond so that an attack is not favoured.
Thus, the carbon monoxide molecule is one that won’t react with water at all and totally defies the concept of acidic/basic oxides.
Abbreviations:
HOMO is a widely used abbreviation for the Highest Occupied Molecular Orbital, i.e. the one with the highest energy that still contains electrons. It is usually the orbital that will attack nucleophilicly or that will be attacked electrophilicly.
LUMO is a widely used abbreviation for the Lowest Unoccupied Molecular Orbital, i.e. the virtual (unoccupied) orbital that has the lowest energy. When considering a nucleophilic attack, the attacking electrons will usually interact with the LUMO. Electrophiles attack with other molecules’ HOMO with their LUMO.
Explanation:
These types of reactions are called endothermic reactions. This is when the system absorbs the heat from the surrounding. In this case, the system is the chemical reaction and the environment is the direct vicinity of the chemical reaction. You notice that the pack becomes cold because heat from the surrounding is being absorb.
The bonds involved in this substance includes ionic bonding and polar covalent.
