0.025 g
Sig Fig applies only to numbers that not zero, only except when the zero is after the the number.
For example:
0.0255 is three sigfigs
0.0050 is two sig figs
0.0005 is one sigfig
Hey there!
1 mol has 6.022 x 10²³ molecules.
If we have 4.2 mol F₂, multiply the number of molecules in 1 mol by 4.2.
4.2 x 6.022 x 10²³
2 sig figs
25 x 10²³
Put this properly into scientific notation.
2.5 x 10²⁴ molecules of F₂
Hope this helps!
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>