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Harman [31]
4 years ago
15

Which of the following is a chemical change?

Chemistry
2 answers:
FromTheMoon [43]4 years ago
4 0

<u>Answer:</u>

<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>

<u>Explanation:</u>

Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.

Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.

But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.

Naddika [18.5K]4 years ago
4 0

Answer:

Silver tarnishing as the silver metal reacts with sulphur is a chemical change.

Explanation:

Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.

Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.

But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.

Read more on Brainly.com - brainly.com/question/9296511#readmore

Explanation:

You might be interested in
In order to gain one pound of body weight, the average person must consume 3500 more calories
Fed [463]

Answer:

<em>17500 calories</em> of chocolate bars are needed to eat to gain 5 pounds.

Explanation:

We can use ratios to calculate the answer using the information given in the question.

1 pound : 3500 grams

5 pounds : x grams

As it is given that the individual is burning no calories, we do not have to factor in any additional numbers.

<u><em>Method</em><em> </em><em>A</em><em>:</em></u>

To go from 1 in the first ratio to 5 in the second ratio, they multipled 1 by 5. Hence, to go from 3500 in the first ratio to x in the second ratio, we must multiply by 5.

x = 3500 × 5

x = 17500

<em><u>Method B</u>:</em>

To solve for the answer x, we can convert the ratios into fractions.

1 / 5 = 3500 / x

3500 / x = 1 / 5

To make x the subject, multiply the denominator of the left fraction with the numerator of the right fraction and place it on the left side. Then multiply the numerator of the left fraction with the denominator of the right fraction and place it on the right side.

x = 5 × 3500

x = 17500

4 0
4 years ago
Given the reaction:
tino4ka555 [31]

4 moles of NaCl is produced from 2 moles of Na₂CrO₄.

<u>Explanation:</u>

Given reaction is

PbCl₂(aq) + Na₂CrO₄(aq)→ PbCrO₄(s) + 2 NaCl (aq)

It is the balanced equation which means that on both sides of the equation, number of atoms of each element are equal.

From the above balanced equation it says that molar ratio of Na₂CrO₄ to NaCl is 1 : 2.

That is 1 mole of Na₂CrO₄ produces 2 moles of NaCl, so the molar ratio is 1:2.

2 moles of Na₂CrO₄  produces 4 moles of NaCl.

So the molar ratio of Na₂CrO₄ to NaCl is 2: 4.

6 0
3 years ago
Describe how water molecules interact with sodium chloride molecules in order for water to dissolve salt.
Phantasy [73]

Answer:

Sodium chloride is an ionic salt that completely dissociates in water.

Explanation:

Sodium chloride in water dissociates according to the equation.

NaCl (aq) → Na + (aq) + Cl- (aq)

While water stays in balance according to the equation

2H2O (l) ⇄ H3O+(aq)  +  OH-(aq).

By dissociating the solute in the solvent, the water molecules pick up the sodium cations as well as the chloride anions to break the bonds in the salt crystals and thus produce the dissolution

If the ions are analyzed separately, we see that Na + interacts with water, so it would be producing sodium hydroxide, releasing protons.  

If the reaction goes in the sense of products, the Na + would increase the concentration of [H +], however being a neutral salt the pH does not vary from 7, so the reaction would never go in the sense of products, but only reagents. That's why as the sodium hydroxide is a strong base, it only promotes the formation of water and the cation.

Na+  +  H2O  ←  NaOH  +  H+

The same situation occurs with chloride, since no matter how much you want to form hydrochloric acid, it dissociates by promoting the formation of water plus the corresponding anion. Na + and Cl- act as too weak conjugate acid and base, so the reaction would never go in the direction of products

Cl-  +  H2O  ←  HCl  +  OH-

3 0
4 years ago
When snow melts does its volume decrease or increase?
kompoz [17]

The volume of the snow decreases. This had happened because the snow is made up or comprised of water (H2O) and oxygen (O). When the snow starts melting, the air inside the snow discharges into the atmosphere and the water turn out to be a puddle on the ground. 

7 0
3 years ago
Benzoyl chloride, C6H5COCl, reacts with water to form benzoic acid, C6H5COOH, and hydrochloric acid. This first-order reaction i
djyliett [7]

<u>Answer:</u> The time required for the conversion of benzoyl chloride to benzoic acid is 390 seconds.

<u>Explanation:</u>

The expression for the rate law of first order kinetics is given as:

\ln \frac{N}{N_o}=e^{-kt}      ......(1)

where,

N_o = initial mass of isotope = 100 g

N = mass of the parent isotope left after the time = 100 - 25 = 75 g

t = time taken = 26 s

k = rate constant = ?

Putting values in above equation, we get:

\ln \frac{75}{100}=e^{-k\times 26}\\\\k=0.011065s^{-1}

Now, we need to find the time when 99 % of the reaction is complete. Using equation 1 again, we get:

N_o = initial mass of isotope = 100 g

N = mass of the parent isotope left after the time = 100 - 99 = 1 g

t = time taken = ? s

k = rate constant = 0.011065s^{-1}

Putting values in above equation, we get:

\ln \frac{1}{100}=e^{-0.011065\times t}\\\\t=416s

Time required for the conversion of benzoyl chloride to benzoic acid = 416 - 26 = 390 s

8 0
3 years ago
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