The atomic number of Be is 4, and so it has 2 shells. There are valence electrons in the second, which is the outermost, shell of Be. To get the element with one more shell, there would be 3 shells on the new element, and 1 less valence electron, so the new element should have 1 valence electron. Sodium is the element with 3 shells, and one valence electron which fits perfectly into the description.
<h2> The correct option is (a).</h2>
Explanation:
- There is no change of state in pouring water into a vacuum insulated bottle as the vacuum created inside the bottle only reduces the time limit for the transfer of heat by conduction and convection.
- It helps the content filled in the bottle to be hot and cool for a longer time.
Hence, option (a) is correct.
Rest of the options (b), (c), (d), (e) is not correct because of the following reasons:
- In the sublimation of dry ice, the dry ice (solid-state) is changed to the vapour form.
- In the freezing of water, the liquid state is changed to solid-state.
- During the vaporization of alcohol, the liquid state is changed to the vapour form.
- During the melting of ice, the solid-state is changed to the liquid state.
Answer:
The answer is 2,3-dimethylbutan-2-ol and the structure is attached below.
Explanation:
Although we are not provided with ¹H-NMR spectrum and IR spectrum but still we can elucidate the ¹³C-NMR data and finalize a plausible structure.
First of all we look at the molecular formula, we can conclude from the formula that the structure given is saturated in nature because the hydrogen deficiency index of this formula is zero. Hence, we can say that there is no double bond either between Carbon atoms or between carbon and oxygen atom. This can also be proved by the absence of peaks in downfield as unsaturated compounds and carbonyl compounds give value above 100 and 200 ppm respectively.
Secondly, we can also conclude that among the six carbon atom two pairs of them are having same electronic environment because we are having only 4 signals hence we can conclude that two pairs have same chemical shift values.
Also, after making every possinble isomer of given molecular formula the structure of 2,3-dimethylbutan-2-ol was found to be the most accurate structure.
Answer:
6.21 moles O
Explanation:
To find the moles of oxygen, you need to (1) convert grams Mn(ClO₄)₄ to moles Mn(ClO₄)₄ (via molar mass) and then (2) convert moles Mn(ClO₄)₄ to moles O (via mole-to-mole ratio from formula subscripts). It is important to arrange the conversions/ratios in a way that allows for the cancellation of units.
Molar Mass (Mn(ClO₄)₄): 452.74 g/mol
1 Mn(ClO₄)₄ = 1 Mn and 4 Cl and 16 O
175.7 g Mn(ClO₄)₄ 1 mole 16 moles O
--------------------------- x ------------------- x --------------------------- = 6.21 moles O
452.74 g 1 mole Mn(ClO₄)₄
