Physical changes happen when you do/mix something that can be reversed. Best example is ripping a paper, you can just tape it back together so it is just an observable thing that changes, which is a physical change. Chemical changes happen when you mix things and they make a new substance and can’t be reversed. The best example of this is the Statue of Liberty, which changed in color due to the chemical change between the oxygen and copper, which created a new substance (rust) which made it green instead of copper.
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Double replacement.
Ba(OH)2 + H2SO4 ====> 2H2O + BaSO4
Answer:
Saturation.
Explanation:
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In this case, the statement is accounting for the saturation vapor pressure as it is the pressure of a vapor which is in equilibrium with its liquid, in other words it is the maximum exerted pressure possible by the vapor at a given temperature or just the maximum amount of the vapor, so there is neither no more vapor that could condense nor more liquid that could boil.
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Answer:
See explanation and image attached
Explanation:
This reaction is known as mercuric ion catalyzed hydration of alkynes.
The first step in the reaction is attack of the mercuric ion on the carbon-carbon triple bond, a bridged intermediate is formed. This bridged intermediate is attacked by water molecule to give an organomercury enol. This undergoes keto-enol tautomerism, proton transfer to the keto group yields an oxonium ion, loss of the mercuric ion now gives equilibrium keto and enol forms of the compound. The keto form is favoured over the enol form.
Explanation:
Expression for the
speed is as follows.

where,
= root mean square speed
k = Boltzmann constant
T = temperature
M = molecular mass
As the molecular weight of oxygen is 0.031 kg/mol and R = 8.314 J/mol K. Hence, we will calculate the value of
as follows.

= 
= 498.5 m/s
Hence,
for oxygen atom is 498.5 m/s.
For nitrogen atom, the molecular weight is 0.028 kg/mol. Hence, we will calculate its
speed as follows.

= 
= 524.5 m/s
Therefore,
speed for nitrogen is 524.5 m/s.