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3 years ago

At STP, an element that is a brittle solid and a poor conductor of heat and electricity could have an atomic number of

Chemistry

2 answers:

CaHeK987 [17]3 years ago

5 0

(3) 16, which is Sulfer.

Anuta_ua [19.1K]3 years ago

4 0

Answer: Option (2) is the correct answer.

Explanation:

It is known that non-metals do not conduct electricity.

Carbon has atomic number 12, sulfur has atomic number 16, and chlorine has an atomic number 17. All these elements are non-metals.

Whereas aluminium has atomic number 13 and it is a poor metal.

So, aluminium being a poor metal is a brittle solid and a poor conductor of heat and electricity.

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A concentration cell consists of two Zn/Zn2+ half-cells. The concentration of Zn2+ in one of the half-cells is 2.0 M and the con

inna [77]

Answer: The EMF of the cell is coming when the cell having diluted concentration is getting oxidized.

Explanation:

We are given a cell which contains two $Zn/Zn^{2+}$ half cells. This means that the standard electrode potential of the cell will be 0.

For a reaction to be spontaneous, the EMF of the cell must be positive. If the EMF of the cell is negative, the reaction will be non-spontaneous and will not take place.

For a reaction to be spontaneous, the diluted cell must get oxidized.

The half reaction for the given cell follows:

Oxidation half reaction: $Zn\rightarrow Zn^{2+}(1.0\times 10^{-3}M)+2e^-$

Reduction half reaction: $Zn^{2+}(2.0M)+2e^-\rightarrow Zn$

Net reaction: $Zn^{2+}(2.0M)\rightarrow Zn^{2+}(1.0\times 10^{-3}M)$

To calculate the EMF of the cell, we use Nernst equation:

$E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Zn^{2+}_\text{{(diluted)}}]}{[Zn^{2+}_{\text{(concentrated)}}]}$

where,

n = number of electrons in oxidation-reduction reaction = 2

$E_{cell}$ = ?

$[Zn^{2+}_{\text{(diluted)}}]$ = $1.0\times 10^{-3}M$

$[Zn^{2+}_{\text{(concentrated)}}]$ = 2.0 M

Putting values in above equation, we get:

$E_{cell}=0-\frac{0.0592}{2}\log \frac{1.0\times 10^{-3}M}{2.0M}$

$E_{cell}=0.097V$

Hence, the EMF of the cell is coming when the cell having diluted concentration is getting oxidized.

6 0

3 years ago

Distinguish between zinc nitrate and lead nitrate

Kobotan [32]

Answer:

Zinc nitrate gives white ppt. which dissolves in excess ammonium hydroxide and produce a colorless solution whereas lead nitrate gives a chalky white ppt. of lead hydroxide which doesnot dissolve.

Explanation:

Hope this helps :)

7 0

3 years ago

Explain Charles law

kodGreya [7K]

"Charles Law" is the relationship between "volume-temperature" (V ∝ T).

Explanation:

Charles Law is basically volume-temperature relationship (V ∝ T). French scientist “Jacques Charles” in 1787 studied effect of temperature on the volume of gases at constant pressure, which described how gases manage to expand when heated. Law stated as “At constant pressure, the volume of a given "mass" of a gas decreases or increases by 1/273 of its volume at $0^{\circ} \mathrm{C}$ for each one degree rise or fall in temperature”. Formula derived from law is as follows: $\mathbf{V}_{\mathbf{t}}=\mathbf{V}_{0}[\mathbf{1}+\mathbf{t} / \mathbf{2} 7 \mathbf{3}]$ here ${V}_{0}$ is volume of given mass of a gas at $0^{\circ} \mathrm{C}$ , ${V}_{t}$ is its volume at any temperature $t^{\circ} \mathrm{C}$ . Application of Charles law is hot air balloons.

8 0

3 years ago

A titanium cube contains 2.86×10^23 atoms. What is the edge length of the cube? The density of titanium is 4.50 g/cm^3. (The vol

Arada [10]

Answer: 1.72cm

Explanation:

First let us calculate the mass of titanium that contain 2.86×10^23 atoms..

1mole of a substance contains 6.02x10^23 atoms as we have come to understand from Avogadro's hypothesis. Therefore, 1mole of titanium also contains 6.02x10^23 atoms.

1mole of titanium = 48g

1mole (i.e 48g) of titanium contains 6.02x10^23 atoms,

Therefore Xg of titanium will contain 2.86×10^23 atoms i.e

Xg of titanium = (48x2.86×10^23)/6.02x10^23 = 22.8g

Next, we must find the volume of titanium

Density of titanium = 4.5g/cm^3

Mass of titanium = 22.8g

Volume =?

Density = Mass /volume

Volume = Mass /Density

Volume = 22.8/4.5

Volume = 5.07cm^3

Now we can find the edge length:

Volume = 5.07cm^3

Length =?

V = L^3

L = cube root (V)

L = cube root (5.07)

L = 1.72cm

6 0

3 years ago

A change in position of an object is its

Nezavi [6.7K]

Answer:

Speed

Explanation:

3 0

3 years ago