How many total oxygen atoms are in lead (II) nitrate? * Pb(NO3)2

Scientists developed symbols and gave the elements numbers to help organize the elements by their chemical properties. The periodic table helps identify the underlying chemical and physical traits of the elements.

4 0

3 years ago

Can some atoms exceed the limits of the octet rule in bonding? If so, give an example.

harkovskaia [24]

Answer:

Yes. Example: Sulfur hexafluoride (SF₆) molecule

Explanation:

According to the octet rule, elements tend to form chemical bonds in order to have 8 electrons in their valence shell and gain the stable s²p⁶ electronic configuration.

However, this rule is generally followed by main group elements only.

Exception: SF₆ molecule

In this molecule, six fluorine atoms are attached to the central sulfur atom by single covalent bonds.

Each fluorine atom has 8 electrons in their valence shells. Thus, it follows the octet rule.

Whereas, there are 12 electrons around the central sulfur atom in the SF₆ molecule. Therefore, sulfur does not follow the octet rule.

Therefore, the SF₆ molecule is known as a hypervalent molecule or expanded-valence molecule.

6 0

3 years ago

• We obtained the above 10.00-mL solution by diluting a stock solution using a 1.00-mL aliquot and placing it into a 25.00-mL vo

garik1379 [7]

Answer:

a) The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.

b) 0.0035 mole

c) 0.166 M

Explanation:

Phosphoric acid is tripotic because it has 3 acidic hydrogen atom surrounding it.

The equation of the reaction is expressed as:

$H_3PO_4 \ + \ 3NaOH -----> Na_3 PO_4 \ + \ 3H_2O$

1 mole 3 mole

The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.

b) if 10.00 mL of a phosphoric acid solution required the addition of 17.50 mL of a 0.200 M NaOH(aq) to reach the endpoint; Then the molarity of the solution is calculated as follows

$H_3PO_4 \ + \ 3NaOH -----> Na_3 PO_4 \ + \ 3H_2O$

10 ml 17.50 ml

(x) M 0.200 M

Molarity = $\frac{0.2*17.5}{1000}$