Answer:
Bromine (Br)
Explanation:
Im assuming thats the answer you are looking for since you didnt include any options :,)
Answer:
(a) Condensation:Exothermic
(b) Sublimation: Endothermic
(c) Vaporization: Endothermic
(d) Freezing: Exothermic
Explanation:
When a phase change occurs, for example going from a liquid to a gas we need to increase the kinetic energy of the molecules to escape to the gas phase where the kinetic energy of the molecules is greater. By the contrary if we remove energy we slow down the molecules increasing their atttraction and slowing them as it occurs when the goes into the liquid state, hence this phase change is exothermic.
(a) Condensation : when the phase change is from a gas by definition we have a condensation phase chanhe. The reaction is exothermic, we need to cool the gas to condense.
(b) Sublimation: crystals of iodine disappear from an evaporating dish as they stand in a fume hood : this phase change receives the name of sublimation and it occurs when a solid goes directly to the gas phase without going through the liquid phase. We need to increase the energy of the molecules so it can go to the gas phase and the change is endothermic.
(c) Vaporization : rubbing alcohol in an open container slowly disappears: this phase change is vaporization and by difinition is when the liquid goes to the gas phase, hence its name vaporization. The change is endothermic, we need heat from the sorroundings to give the molecules of the liquid enough energy to escape into the vapor phase.
(d) Molten lava from a volcano turns into solid rock : this phase change is freezing and we need to lower the energy of the liquid by releasing it to the sorroundings, therore it is an exothermic phase change.
The question is missing the molecules in which the integration ratio of 2:3 will be observed. The complete question is given in the attachment.
Answer:
Molecule (a), (c), and (f) will show two peaks with the integration ratio of 2:3 in their 1H NMR spectrum
Explanation:
In the 1H NMR spectrum, the peak area is dependent on the number of hydrogen in a specific chemical environment. Hence, the ratio of the integration of these signals provides us with the relative number of hydrogen in two peaks. This rationale is used for the assignment of molecules that will give 2:3 integration ratio in the given problem.
- Molecule (a) have two CH₂ and three CH₃ groups. Hence, it will give two peaks and their integration ratio becomes 2:3 (Answer)
- Molecule (b) contains three chemical environments for its hydrogen atoms
- Molecule (c) have a single CH₂ and CH₃ group giving integration ratio of 2:3 (Answer)
- Molecule (d) will give two peaks but their ratio will be 1:3 because of two hydrogens of CH₂ and six hydrogens from two CH₃ groups
- Molecule (e) have three CH and three CH₃ groups, so their ratio will become 1:3
- Molecule (f) contains four CH and two CH₃ groups, giving two peaks. So, the integration ratio of their peaks is 2:3 (Answer)
- Molecules
- (g)
- and
- (h)
- both have two CH and two CH₃ groups giving two peaks with the integration ratio of 1:3
2 Na(s) + Cl₂(g) = 2 NaCl(s) 22,4 L in STP
Number of moles :
n = m / molar mass
Na = 103.0 / 22.98
Na = 4.48 moles
Cl₂ ( is limiting reagent )
13 L / 22,4 L = 0.580 moles Cl₂
2 ( Sodium stoichiometric coefficient)* 0.580 = 1.16 mol NaCl
Molar mass NaCl = 58.44 g/mol
1.16 * 58.44 = 67.7904 g of NaCl
hope this helps!