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3 years ago

Which of the following statements about metal elements is correct?

Chemistry

1 answer:

Sati [7]3 years ago

4 0

Answer: C. Metals tend to easily lose their valence electrons.

Explanation:

Metals are those substances which have tendency to loose their valence electrons to attain noble gas configuration and forms positive ions called as cations.

Example: Gold, potassium etc

$M\rightarrow M^++e^-$

Non metals are those substances which have tendency to gain valence electrons to attain noble gas configuration and form negative ions called as anions.

Example: Sulphur, Chlorine

$N+e^-\rightarrow N^-$

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The standard emf for the cell using the overall cell reaction below is +2.20 V:

ANEK [815]

Answer:

emf generated by cell is 2.32 V

Explanation:

Oxidation: $2Al-6e^{-}\rightarrow 2Al^{3+}$

Reduction: $3I_{2}+6e^{-}\rightarrow 6I^{-}$

---------------------------------------------------------------------------------

Overall: $2Al+3I_{2}\rightarrow 2Al^{3+}+6I^{-}$

Nernst equation for this cell reaction at $25^{0}\textrm{C}$ -

$E_{cell}=E_{cell}^{0}-\frac{0.059}{n}log{[Al^{3+}]^{2}[I^{-}]^{6}}$

where n is number of electrons exchanged during cell reaction, $E_{cell}^{0}$ is standard cell emf , $E_{cell}$ is cell emf , $[Al^{3+}]$ is concentration of $Al^{3+}$ and $[Cl^{-}]$ is concentration of $Cl^{-}$

Plug in all the given values in the above equation -

$E_{cell}=2.20-\frac{0.059}{6}log[(4.5\times 10^{-3})^{2}\times (0.15)^{6}]V$

So, $E_{cell}=2.32V$

3 0

3 years ago

Give an example of two elements that would form a covalent bond

Tamiku [17]

<span>Hydrogen carbon and oxygen commonly form covalent bonds.
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HOPE THIS HELPS!

4 0

3 years ago

Calculate the atomic mass of Carbon if the two common isotopes of carbon have masses of

Mars2501 [29]

Answer:

Average atomic mass of carbon = 12.01 amu.

Explanation:

Given data:

Abundance of C¹² = 98.89%

Abundance of C¹³ = 1.11%

Atomic mass of C¹² = 12.000 amu

Atomic mass of C¹³ = 13.003 amu

Average atomic mass = ?

Solution:

Average atomic mass of carbon = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass of carbon = (12.000×98.89)+(13.003×1.11) /100

Average atomic mass of carbon= 1186.68 + 14.43333 / 100

Average atomic mass of carbon = 1201.11333 / 100

Average atomic mass of carbon = 12.01 amu.

5 0

3 years ago

Enter a balanced equation for the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II

Dominik [7]

Answer:

Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)

Explanation:

Let's consider the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.

Pb(NO₂)₂(aq) + LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)

This is a double displacement reaction. We will start balancing Cl by multiplying LiCl by 2.

Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)

Now, we have to balance Li by multiplying LiNO₂ by 2.

Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)

The equation is now balanced.

4 0

3 years ago

A cylinder is labeled \"PENTANE.\" When the gas inside the cylinder is monochlorinated, five isomers of formula C5H11Cl result.

melisa1 [442]

Answer:

a mixture of two these

Explanation:

The number of isomeric monochlorides depends on the structure and number of equivalent hydrogen atoms in each isomer of pentane.

n-pentane has three different kinds of equivalent hydrogen atoms leading to three isomeric monochlorides formed.

Isopentane has four different types of equivalent hydrogen atoms hence four isomeric monochlorides are formed.

Lastly, neopentane has only one type of equivalent hydrogen atoms that yields one mono chlorination product.

Hence the cylinder must contain a mixture of isopentane and neopentane which yields four and one isomeric monochlorides giving a total of five identifiable monochloride products as stated in the question.

8 0

3 years ago