Answer:
c tarnishes in air
Explanation:
After silver has been exposed to air that contains sulphur gases, discoloration would occur. there would be darkening that is caused by the reaction with gases.When any silver object tarnishes, it brings about a disfiguring of that object. Hydrogen sulphide would be needed for this to happen. silver sulphide is black and a if a thin layer should form on any surface, it ill darken it. This is what we refer to as tarnishing.
Answer:

Explanation:
In this problem, the temperature stays constant. The volume and pressure change, so we use Boyle's Law. This states that the pressure of a gas is inversely proportional to the volume. The formula is:

Now we can substitute any known values into the formula.
Originally, the gas has a volume of 25.0 liters and a pressure of 2.05 atmospheres.

The volume is decreased to 14.5 liters, but the pressure is unknown.

Since we are solving for the new pressure, or P₂, we must isolate the variable. It is being multiplied by 14.5 liters and the inverse of multiplication is division. Divide both sides by 14.5 L .


The units of liters cancel.



The original values of volume and pressure have 3 significant figures, so our answer must have the same.
For the number we found, that is the hundredth place.
The 4 in the thousandth place (in bold above) tells us to leave the 3 in the hundredth place.

The new pressure is approximately <u>3.53 atmospheres.</u>
Answer:
The answer for the calculation is as follows
17.48373
52 g of hydrogen H₂
Explanation:
I will assume that the problem is talking about the hydrogenation of carbon dioxide CO₂ not carbon monoxide CO. It is harder to reduce carbon dioxide than carbon monoxide and if you manage to reduce carbon dioxide you can reduce the carbon monoxide as well.
This reaction it will take place in the presence of catalyst at a specific temperature and pressure.
CO₂ + 4 H₂ → CH₄ + 2 H₂O
Now taking into the account the chemical reaction we devise the following reasoning:
if 1 mole of CO₂ react with 4 moles of H₂
then 6.5 moles of CO₂ react with X moles of H₂
X = (6.5 × 4) / 1 = 26 moles of H₂
number of moles = mass / molecular wight
mass = number of moles × molecular wight
mass of H₂ = 26 × 2 = 52 g
Learn more about:
hydrogenation reaction
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