Answer:
Last option is the correct choice.
Explanation:
Number of protons = 60-33 = 27
Superscript 60 Subscript 27 upper C o.
Best Regards!
Answer:
ΔH°_rxn = -195.9 kJ·mol⁻¹
Explanation:
4NH₃(g) + 3O₂(g) ⟶ 2N₂(g) +6H₂O(g)
ΔH°_f/(kJ·mol⁻¹): -45.9 0 0 -241.8
The formula relating ΔH°_rxn and enthalpies of formation (ΔH°_f) is
ΔH°_rxn = ΣΔH°_f(products) – ΣΔH°_f(reactants)
ΣΔH°_f(products) = -6(241.8) = -1450.8 kJ
ΣΔH°_f(reactants) = -4(45.9) = -183.6 kJ
ΔH°_rxn = (-1450.8 + 183.6) kJ = -1267.2 kJ
The question is incomplete. Complete question is attached below:
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Correct Answer:
Option A i.e FlammabilityReason:
Hydrochloric acid is a
strong acid. It has a high value of dissociation constant. Following equilibrium is established with HCl is dissolved in water
HCl + H2O ↔ Cl- + H3O+
Above, reaction is highly exothermic in nature. So care must be taken while preparing HCl solution of desired concentration.
HCl must be added in beaker containing water. Reversed, i.e. adding water in HCl, must never be done. This is because when acid is poured into water, it flows down the flask and mixes much efficiently and no boiling occurs. On other hand, <span> when water is added to acid, the very first drop of water will react with acid. The heat generated during this event might be high enough to boil the water instantly, which could spray acid out of the container.
The physical contact with concentration HCl will result in skin burn. As well, inhaling</span><span> HCl vapors can cause burns to body tissues, lung damage and even death in extreme cases. Also, since HCl is a strong acid, it would undergoes reaction almost spontaneously, which would inturn favour substitution reaction. However,
HCl is not a flammable gas. Hence, it is of no concern while performing substitution reaction. </span>
Answer:
If both fluorine atoms are combine than each atom have 8 valance electrons and total valance electrons in both atoms are 16.
Explanation:
Fluorine is halogen atom. The elements of group 17 are called halogens. These are six elements Fluorine, Chlorine, Bromine, Iodine, Astatine. Halogens are very reactive these elements can not be found free in nature. Their chemical properties are resemble greatly with each other. As we move down the group in periodic table size of halogens increases that's way fluorine is smaller in size as compared to other halogens elements.
There seven valance electrons in each halogen atom. They need one electron to complete the octet.
Fluorine atom combine with its another atom through covalent bond and share its one of valance electron with other atom thus both have 8 valance electrons and total valance electrons in both atoms are 16.
Answer:
Todas son correctas
Explanation:
I) Los compuestos del carbono son solubles en disolventes no polares como el hexano, benceno, éter, etc. <em>VERDADERO. </em>La mayoría de los compuestos de carbono son apolares, y basados en la regla: Similar disuelve similar, podemos presumir que la mayoría de compuestos de carbono se disuelven en solventes no polares.
II) Los compuestos del carbono generalmente presentan puntos de fusión y de ebullición bajos. <em>VERDADERO. </em>Al ser sustancias apolares, sus fuerzas electrostáticas son bajas. De la misma manera, como su masa atómica es pequeña, las fuerzas de Van der Waals son despreciables haciendo que sus puntos de fusión y ebullición sean bajos respecto a sustancias de estrucutra similar.
III) La gran mayoría de los compuestos del carbono son combustibles, sean estos, gaseosos, líquidos o sólidos. <em>VERDADERO. </em>Los gases (Como el gas natural) son combustibles usados para cocina. Los líquidos (Como la gasolina) son combustibles y bastante inflamables. Los sólidos (Como la madera) se usan como combustibles para hacer asados o son el combustible en incendios forestales.
IV) El enlace covalente es característico de los compuestos del carbono. <em>VERDADERO. </em>La polaridad del carbono es neutral haciendo que la mayoría de los enlaces que forma sean covalentes.
<h3>Todas son correctas
</h3>