What are the oxidation numbers of the elements in the nitrite ion, no2−?

Why does the octet rule not always refer to a stable arrangement of eight valence electrons

bearhunter [10]

Answer:

Explanation:

The octet rule does not always refer to a stable arrangement of eight valence electrons because there are some element that do not have eight valence electrons yet they are stable. for example;

i) Helium, It has two valence electrons and it is a stable gas.

ii) Boron triflouride (BF3); it has six valence electrons (deficit valence electron) yet it is also stable.

iii) Phosphorus pentachloride (PCl5); it has more than eight valence electron and it is also stable.

For these few reasons it is not always advisable to say octet arrangement refer to stable eight valence electrons.

4 0

3 years ago

A student dissolves 0.0688 mol of sodium hydroxide in water to make a 0.250 L solution. What is the molarity of the solution?

den301095 [7]

Number of moles = 0.0688 moles of NaoH

volume = 0.250 L

Molarity = moles of solute / volume ( L )

M = 0.0688 / 0.250

M = 0.28 M

Answer B

7 0

3 years ago

Hydrogen, a potential future fuel, can be produced from carbon (from coal) and steam by the following reaction: C(s)+2H2O(g)→2H2

madam [21]

The question is incomplete , complete question is:

Hydrogen, a potential future fuel, can be produced from carbon (from coal) and steam by the following reaction:

$C(s)+ 2 H_2O(g)\rightarrow 2H_2(g)+CO_2(g).\Delta H=?$

Note that the average bond energy for the breaking of a bond in CO2 is 799 kJ/mol. Use average bond energies to calculate ΔH of reaction for this reaction.

Answer:

The ΔH of the reaction is -626 kJ/mol.

Explanation:

$C(s)+ 2 H_2O(g)\rightarrow 2H_2(g)+CO_2(g).\Delta H=?$

We are given with:

$\Delta H_{H-O}=459 kJ/mol$