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3 years ago

What is the most likely charge on an ion formed by an element with a valence electron configuration of ns2np4

Chemistry

1 answer:

Andreas93 [3]3 years ago

6 0

Answer:

Explanation:

For an element to be stable, it must follow the octet rule: an atom will gain, lose or share electrons until its valence shell is complete with 8 electrons.

An element with the valence electron configuration ns²np⁴ has 6 (2+4) electrons in its valence shell. Thus, in order to fulfill the octet, it will gain 2 electrons. As a consequence, it will form an anion with charge 2-.

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What action would you expect an atom of Aluminum to undergo?

KATRIN_1 [288]

Answer:

C. Lose three electrons to have a full outer shell

Explanation:

Al is in Group 13 of the Periodic Table, so it has three valence electrons.

It must either lose three electrons or gain five to achieve a stable octet.

It is easier to lose three electrons than it is to gain five, so Al loses three electrons.

D. is wrong, for the same reason.

A. is wrong. If Al lost three electrons, it would be breaking into a stable inner shell.

C. is wrong. Al is a metal, so it will lose electrons in a reaction.

6 0

4 years ago

Determine how many millilitres of a 4.25 M HCl solution are needed to react completely with 8.75 g CaCO3?

Helen [10]

Answer:

41 mL

Explanation:

Given data:

Milliliter of HCl required = ?

Molarity of HCl solution = 4.25 M

Mass of CaCO₃ = 8.75 g

Solution:

Chemical equation:

2HCl + CaCO₃ → CaCl₂ + CO₂ + H₂O

Number of moles of CaCO₃:

Number of moles = mass/molar mass

Number of moles = 8.75 g / 100.1 g/mol

Number of moles = 0.087 g /mol

Now we will compare the moles of CaCO₃ with HCl.

CaCO₃ : HCl

1 : 2

0.087 : 2/1×0.087 = 0.174 mol

Volume of HCl:

Molarity = number of moles / volume in L

4.25 M = 0.174 mol / volume in L

Volume in L = 0.174 mol /4.25 M

Volume in L = 0.041 L

Volume in mL:

0.041 L×1000 mL/ 1L

41 mL

8 0

3 years ago

An ideal gas sealed in a rigid 4.86-L cylinder, initially at pressure Pi=10.90 atm, is cooled until the pressure in the cylinder

seraphim [82]

Answer:

$\Delta H=-11897J$

Explanation:

Hello,

In this case, it is widely known that for isochoric processes, the change in the enthalpy is computed by:

$\Delta H=\Delta U+V\Delta P$

Whereas the change in the internal energy is computed by:

$\Delta U=nCv\Delta T$

So we compute the initial and final temperatures for one mole of the ideal gas:

$T_1= \frac{P_1V}{nR}=\frac{10.90atm*4.86L}{0.082*n}=\frac{646.02K }{n} \\\\T_2= \frac{P_2V}{nR}=\frac{1.24atm*4.86L}{0.082*n}=\frac{73.49K }{n}$

Next, the change in the internal energy, since the volume-constant specific heat could be assumed as ³/₂R:

$\Delta U=1mol*\frac{3}{2} (8.314\frac{J}{mol*K} )*(73.49K-646.02K )=-7140J$

Then, the volume-pressure product in Joules:

$V\Delta P=4.86L*\frac{1m^3}{1000L} *(1.24atm-10.90atm)*\frac{101325Pa}{1atm} \\\\V\Delta P=-4756.96J$

Finally, the change in the enthalpy for the process:

$\Delta H=-7140J-4757J\\\\\Delta H=-11897J$

Best regards.

7 0

4 years ago

Acid base neutralization reactions (e.g.titrations can be considered to go to completely to the right (to products.

aivan3 [116]

Acid base neutralization reaction is a chemical reaction between acid and base, which will result into water and a salt. this is neutralization because the product of the reaction which is water is neutral, the pH is 7 and the salt as well

3 0

3 years ago

How much water would I need to add to 700 mL of a 2.7 M KCl solution to make a 1.0 M solution?

geniusboy [140]

Answer:

$1190\ \text{mL}$