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2 years ago

How can you identify gas in a chemical reaction without observing the atoms or molecules?

Chemistry

1 answer:

nikitadnepr [17]2 years ago

5 0

Answer:

There are five signs of a chemical change:

Colour Change.

Production of an odour.

Change of Temperature.

Evolution of a gas (formation of bubbles)

Precipitate (formation of a solid).

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Potassium thiocyanate, KSCN, is often used to detect the presence of Fe3+ ions in solution through the formation of the red Fe(H

Natalija [7]

Answer:

Ferric ions left in the solution at equilibrium is $8.0\times 10^{-6} M$ .

Explanation:

Moles of ferric nitrate in 0.700 L = n

Volume of the solution = V = 0.700 L

Molarity of ferric nitrate = M = 0.00150 M

$n=M\times V=0.00150 M\times 0.700 L=0.00105 mol$

Moles of potassium thiocyanate in 0.700 L = n'

Volume of the potassium thiocyanate solution = V' = 0.700 L

Molarity of potassium thiocyanate = M' = 0.200 M

$n'=M'\times V'=0.200 M\times 0.700 L=0.140 mol$

Molarity of ferric ions after mixing :

1 mol of ferric nitrate gives 1 mol of ferric ions.Then 0.00105 mol ferric nitrate will :

Moles of ferric ions = 0.00105 mol

$M_1=\frac{0.00105 mol}{0.700 L+0.700 L}=0.00075 M$

Molarity of thiocyanate ions after mixing :

1 mol of potassium thiocyanate gives 1 mol of thiocyanate ions.Then 0.140 mol potassium thiocyanate will give:

Moles of thiocyanate ions = 0.140 mol

$M_2=\frac{0.140 mol}{0.700 L+0.700 L}=0.1 M$

Complex equation:

$Fe^{3+}+SCN^-\rightleftharpoons [Fe(SCN)]^{2+}$

0.00075 M 0.1 M 0

At equilibrium:

(0.00075 M -x) (0.1 M-x) x

The formation constant of the given complex = $K_f=8.9\times 10^2$

$K_f=\frac{[[Fe(SCN)]^{2+}]}{[[Fe^{3+}]][SCN^{-}]}$

$8.9\times 10^2=\frac{x}{(0.00075 M -x)\times (0.1 M-x)}$

Solving for x:

x = 0.000742 M

Ferric ions left in the solution at equilibrium :

= (0.00075 M -x) = (0.00075 M - 0.000742 M)= $8.0\times 10^{-6} M$

5 0

3 years ago

Which substances are released during cellular respiration?

scZoUnD [109]

Answer is: carbon dioxide and water <span>are released during cellular respiration.
</span>Chemical reaction of cellular respiration:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O.
There are 18 oxygen atoms (six in glucose and twelve in six molecules of oxygen) in left side of chemical reaction and also 18 oxygen atoms (twelve in six molecules of carbon dioxide and six in six molecules of water) at the right.

8 0

2 years ago

For some disorders, any child, male or female, would have to inherit two copies of the affected gene.

saw5 [17]

Answer:

i think its cystic fibrosis

Explanation:

im so sorry if this is wrong

4 0

2 years ago

What are to long term impacts that the concept of matter cannot be destroyed or created

Tcecarenko [31]

As long as matter cannot be destroyed or created , nothing can be gained or lost.

there is zero impact and hence one cannot numerate the impact

8 0

2 years ago

From a scientific viewpoint, why do many desert dwellers elect to wear white or light-colored garments

alexandr1967 [171]

Darker colors absorb sunlight more, so it will become hotter. Lighter colored clothes will better reflect sun so they will be less hot.

Hope that helped

7 0

3 years ago