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2 years ago

What characterizes a radioactive atom?

Chemistry

1 answer:

Doss [256]2 years ago

4 0

. Its nucleus is unstable.

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1. The solubility of lead(II) chloride at some high temperature is 3.1 x 10-2 M. Find the Ksp of PbCl2 at this temperature.

solniwko [45]

Answer:

1) The solubility product of the lead(II) chloride is $1.2\times 10^{-4}$ .

2) The solubility of the aluminium hydroxide is $1.6\times 10^{-10} M$ .

3)The given statement is false.

Explanation:

Solubility of lead chloride = $S=3.1\times 10^-2M$

$PbCl_2(aq)\rightleftharpoons Pb^{2+}(aq)+2Cl^-(aq)$

S 2S

The solubility product of the lead(II) chloride = $K_{sp}$

$K_{sp}=[Pb^{2+}][Cl^-]^2$

$K_{sp}=S\times (2S)^2=4S^3=4\times (3.1\times 10^{-2})^3=1.2\times 10^{-4}$

The solubility product of the lead(II) chloride is $1.2\times 10^{-4}$ .

Concentration of aluminium nitrate = 0.000010 M

Concentration of aluminum ion = $1\timed 0.000010 M=0.000010 M$

Solubility of aluminium hydroxide in aluminum nitrate solution = $S$

$Al(OH)_3(aq)\rightleftharpoons Al^{3+}(aq)+3OH^-(aq)$

S 3S

The solubility product of the aluminium nitrate = $K_{sp}=1.0\times 10^{-33}$

$K_{sp}=[Al^{3+}][OH^-]^3$

$1.0\times 10^{-33}=(0.000010+S)\times (3S)^3$

$S=1.6\times 10^{-10} M$

The solubility of the aluminium hydroxide is $1.6\times 10^{-10} M$ .

$Molarity=\frac{Moles}{Volume (L)}$

Mass of NaCl= 3.5 mg = 0.0035 g

1 mg = 0.001 g

Moles of NaCl = $\frac{0.0035 g}{58.5 g/mol}=6.0\times 10^{-5} mol$

Volume of the solution = 0.250 L

$[NaCl]=\frac{6.0\times 10^{-5} mol}{0.250 L}=0.00024 M$

1 mole of NaCl gives 1 mole of sodium ion and 1 mole of chloride ions.

$[Cl^-]=[NaCl]=0.00024 M$

Moles of lead (II) nitrate = n

Volume of the solution = 0.250 L

Molarity lead(II) nitrate = 0.12 M

$n=0.12 M]\times 0.250 L=0.030 mol$

1 mole of lead nitrate gives 1 mole of lead (II) ion and 2 moles of nitrate ions.

$[Pb^{2+}]=[Pb(NO_2)_3]=0.030 M$

$PbCl_2(aq)\rightleftharpoons Pb^{2+}(aq)+2Cl^-(aq)$

Solubility of lead(II) chloride = $K_{sp}=1.2\times 10^{-4}$

Ionic product of the lead chloride in solution :

$Q_i=[Pb^{2+}][Cl^-]^2=0.030 M\times (0.00024 M)^2=1.7\times 10^{-9}$

$Q_i$ ( no precipitation)

The given statement is false.

3 0

3 years ago

Is O2 always a double bond?

Dima020 [189]

O-O single bonds and H-O single bonds in $\text{H}_2\text{O}_2$ molecules.
H-O single bonds in $\text{H}_2\text{O}$ molecules.
O=O double bonds in $\text{O}_2$ molecules.

<h3>Explanation</h3>

How many valence electrons do atoms in each molecule need for them to be stable?

Each H atom needs two valence electrons to be stable.
Each atom of an element other than H needs eight valence electron to be stable.

There are two H atoms and two O atoms in an $\text{H}_2\text{O}_2$ molecule. Atoms in each $\text{H}_2\text{O}_2$ need $2 \times 1 + 2\times 2 = 6$ more electrons to be stable.
There are two H atoms and one O atom in an $\text{H}_2\text{O}$ molecule. Atoms in each $\text{H}_2\text{O}$ molecule need $2 \times 1 + 2= 4$ more electrons to be stable.
There are two O atoms in an $\text{O}_2$ molecule. Atoms in each $\text{O}_2$ molecule need $2 \times 2 = 4$ more electrons to be stable.

How many chemical bonds in each molecule?

Each chemical bond adds one valence electron to each bonding atom. Each chemical bond connects two atoms. As a result, each chemical bond adds two valence electrons to the molecule.

Each $\text{H}_2\text{O}_2$ molecule needs $6 / 2 = 3$ chemical bonds.
Each $\text{H}_2\text{O}$ molecule needs $4 / 2 = 2$ chemical bonds.
Each $\text{O}_2$ molecule needs $4 /2= 2$ chemical bonds.

What chemical bonds are these? Again, each H atom needs only one more valence electron to be stable. It will share only one electron with O and form one H-O bond. The rest of the chemical bonds are between O atoms.

There are two H atoms in each $\text{H}_2\text{O}_2$ molecule, which form two H-O bonds. Two of the three chemical bonds in this molecule are H-O. The other is an O-O single bond between the two O atoms.
There are two H atoms in each $\text{H}_2\text{O}$ molecule, which form two H-O bonds. Both chemical bonds in this molecule are H-O. There's no O-O bond in this molecule.
There is no H atom in $\text{O}_2$ molecules. Both chemical bonds are between O atoms. However, there are only two O atoms. There must be two chemical bonds between the two O atoms. That bond will be an O-O double bond.

3 0

3 years ago

Read 2 more answers

Which of the following is an example of acceleration?

anzhelika [568]

Answer:

it's either B. or C.. hope this helps!

Explanation:

4 0

3 years ago

Read 2 more answers

Write a balanced chemical equation for the neutralization reaction between phosphoric acid and rubidium hydroxide.

Anastaziya [24]

Phosphoric acid is a weak acid, while rubidium hydroxide is a strong acid.

H₃PO₄ + RbOH --> Rb₃PO₄ + H₂O

We get Rb₃PO₄ because PO₄ has a charge of 3-, that is PO₄³⁻. Rb has a charge of 1+. You give the subscript of one the charge of the other as this is an ionic compound. So you end up with Rb₃PO₄, a neutral compound.

Now let's balance the equation:
H₃PO₄ + 3RbOH --> Rb₃PO₄ + 3H₂O

5 0

3 years ago

The density of a rock that was a mass of 454 grams and a volume of 100 cm3

puteri [66]

Answer:

The answer is

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass of rock = 454 g

volume = 100 cm³

The density of the rock is

$density = \frac{454}{100} = \frac{227}{50} \\$

We have the final answer as

Hope this helps you

3 0

3 years ago