All categories

3 years ago

The phase change h2(g) → h2(s) is called , and the enthalpy change, δh, for this phase change has a sign.

1 answer:

7 0

The phase change H₂(g) → H₂(s) is called deposition, and the enthalpy change, ΔH, for this phase change has a negative (-) sign.
Deposition is a thermodynamic process in which gas transforms into solid without passing through the liquid phase. Example is formin snow in clouds directly from water vapor. In deposition energy is released.

You might be interested in

What is the balance of S8+Br2=S3Br7

GalinKa [24]

Answer:

3S₈ + 28Br₂ => 8S₃Br₇

Explanation:

Start with either sulfur (S) or bromine (Br) and balance ...

3S₈ + Br₂ => 8S₃Br₇ or S₈ + 7/2Br₂ => S₃Br₇

Balance the remaining reactant ...

3S₈ + 56/2Br₂ => 8S₃Br₇

Remove fractions by multiplying by the fraction's denominator

2(3S₈ + 56/2Br₂ => 8S₃Br₇) => 6S₈ + 56Br₂ => 16S₃Br₇

Reduce to smallest whole number ratio => standard equation at STP ...

3S₈ + 28Br₂ => 8S₃Br₇

8 0

3 years ago

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion. B. If both Assertion &amp

Fofino [41]

Answer:

D- Assertion is false and Reason is true

Explanation:

Precipitation is said to have occurred when an insoluble product is formed from soluble ones. Let us take an instance;

BaCl2(aq) + H2SO4(aq) -------> BaSO4(s) + 2HCl(aq)

The barium sulphate so formed is an insoluble product obtained from the reaction of soluble barium chloride and sulphuric acid. This is a typical example of a double replacement reaction as the both ions exchanged partners.

Thus, the assertion is false but the reason is true.

8 0

3 years ago

When fluoride reacts with the metal it forms an F negative ion the fluorine Adam has gained an electron an undergone _______.

Anika [276]

Answer:

Reduction.

Explanation:

Fluorine atom has gained an electron and undergone reduction because when an atom gains electron it reduced itself thus acting as an oxidant to oxidize another atom .

For exam sodium fluoride NaF is a salt when sodium fluoride undergo breakdown at that time the fluoride atom gains an electron and is converted to F- anion by the process called reduction .

4 0

3 years ago

Can you please help on 17 and 18 pleaseeee

nadezda [96]

Answer:

17. Yes, it represents a chemical reaction. This is because new substances were formed from the original substance.

18. (a) Formation of new substances

(b) Evolution or absorption of large quantity of heat

(c)Change in mass of substances

Explanation:

17. In the model above, molecules of a compound of carbon and hydrogen (molecular formula is C2H6) combines with molecular oxygen (O2) to produce two new substances; a compound composed of two oxygen atoms and one carbon atom (CO2) and another compound composed of two atoms of hydrogen and one atom of oxygen (H2O). Since the new substances formed are completely different from the original substances, it a chemical reaction. Also, a large volume of heat would have been given off.

18. To determine if a chemical reaction has occurred, the following observations can be looked out for.

a. Formation of new substances different entirely from the original substances

b. Evolution or absorption of large quantity of heat during the change. Check whether the vessel containing the substances gets hotter or colder.

c. Change in mass of substances. Since new substances are formed in a chemical reaction, there is usually a significant change in mass of the products and reactants.

6 0

3 years ago

Can the process of rusting be called combustion?

gregori [183]

Answer:

no the answer is oxidation

8 0

3 years ago

Read 2 more answers

The phase change h2(g) → h2(s) is called ________, and the enthalpy change, δh, for this phase change has a ________ sign.

The phase change h2(g) → h2(s) is called , and the enthalpy change, δh, for this phase change has a sign.