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2 years ago

Is burning of coal a reversible change??? If yes how?

2 answers:

7 0

No, for coal burning<span> to be a </span>reversible change<span>, you would need the ability to take CO2 and turn it back into solid carbon.</span>

koban [17]2 years ago

5 0

I don't think so. No way that I know anyway. It it could be done then the need for more coal to be mined would have stopped hundreds of years ago. Once coal is burned, it forms water and carbon dioxide (essentially) with some sulfur oxides.

How do you put that back together again. It's a little like humpty dumpty.

You might be interested in

(b)

mixas84 [53]

Answer:

Group 18th

Explanation:

The group 18th of periodic table which is composed of Noble gases mainly was missing from the Mendeleev's periodic table. The reason for this is that Noble gases are least reactive, therefore, it was difficult to predict such elements which do not react with other elements.

4 0

3 years ago

Match the element with its description. Match Term Definition Sodium A) Has properties of both metals and nonmetals Silicon B) H

Novosadov [1.4K]

Answer:

Sodium - malleable, soft, and shiny

Silicon - has properties of both metals and nonmetals

Bromine - highly reactive gas

Argon - non-reactive gas

Explanation:

Sodium is an alkaline metal. Just like other alkaline metals, it's malleable, soft, and shiny.

Silicon is a metalloid. Metalloids are elements that have properties of both metals and nonmetals.

Bromine a highly reactive chemical element. It is a fuming red-brown liquid at room temperature that evaporates to form a similarly coloured gas.

Argon is a noble gas. Just like other noble gases, it's non-reactive.

8 0

3 years ago

II. Ionic Equations

mario62 [17]

Answer:

Complete ionic: $\begin{aligned}& \rm 2\, Ag^{+}\, (aq) + 2\, {NO_3}^{-} \, (aq) + Ca^{2+}\, (aq) + 2\, Cl^{-}\, (aq) \\ & \rm \to 2\, AgCl\, (s) + Ca^{2+}\, (aq) + 2\, {NO_3}^{-}\, (aq)\end{aligned}$ .

Net ionic: $\begin{aligned}& \rm Ag^{+}\, (aq) + Cl^{-}\, (aq) \to AgCl\, (s)\end{aligned}$ .

Explanation:

Start by identifying species that exist as ions. In general, such species include:

Soluble salts.
Strong acids and strong bases.

All four species in this particular question are salts. However, only three of them are generally soluble in water: $\rm AgNO_3$ , $\rm CaCl_2$ , and $\rm Ca(NO_3)_2$ . These three salts will exist as ions:

Each $\rm AgNO_3\, (aq)$ formula unit will exist as one $\rm Ag^{+}$ ion and one $\rm {NO_3}^{-}$ ion.
Each $\rm CaCl_2$ formula unit will exist as one $\rm Ca^{2+}$ ion and two $\rm Cl^{-}$ ions (note the subscript in the formula $\rm CaCl_2\!$ .)
Each $\rm Ca(NO_3)_2$ formula unit will exist as one $\rm Ca^{2+}$ and two $\rm {NO_3}^{-}$ ions.

On the other hand, $\rm AgCl$ is generally insoluble in water. This salt will not form ions.

Rewrite the original chemical equation to get the corresponding ionic equation. In this question, rewrite $\rm AgNO_3$ , $\rm CaCl_2$ , and $\rm Ca(NO_3)_2$ (three soluble salts) as the corresponding ions.

Pay attention to the coefficient of each species. For example, indeed each $\rm AgNO_3\, (aq)$ formula unit will exist as only one $\rm Ag^{+}$ ion and one $\rm {NO_3}^{-}$ ion. However, because the coefficient of $\rm AgNO_3\, (aq)\!$ in the original equation is two, $\!\rm AgNO_3\, (aq)$ alone should correspond to two $\rm Ag^{+}\!$ ions and two $\rm {NO_3}^{-}\!$ ions.

Do not rewrite the salt $\rm AgCl$ because it is insoluble.

$\begin{aligned}& \rm 2\, Ag^{+}\, (aq) + 2\, {NO_3}^{-} \, (aq) + Ca^{2+}\, (aq) + 2\, Cl^{-}\, (aq) \\ & \rm \to 2\, AgCl\, (s) + Ca^{2+}\, (aq) + 2\, {NO_3}^{-}\, (aq)\end{aligned}$ .

Eliminate ions that are present on both sides of this ionic equation. In this question, such ions include one unit of $\rm Ca^{2+}$ and two units of $\rm {NO_3}^{-}$ . Doing so will give:

$\begin{aligned}& \rm 2\, Ag^{+}\, (aq) + 2\, Cl^{-}\, (aq) \to 2\, AgCl\, (s)\end{aligned}$ .

Simplify the coefficients:

$\begin{aligned}& \rm Ag^{+}\, (aq) + Cl^{-}\, (aq) \to AgCl\, (s)\end{aligned}$ .

7 0

2 years ago

Fission and Fusion of Atomic Nuclei:

bogdanovich [222]

Answer:

C B A D

Explanation:

6 0

3 years ago

An ambulance took 2 hours to cover a distance of 10 kilometers. Find its speed.

bekas [8.4K]

Answer:

5km/hour

Explanation:

2hours = 10km

/2 /2

1 hour = 5km

7 0

2 years ago

Read 2 more answers