The formula used for determining gas pressure, volume and temperature interaction would be PV=nRT.
<span>• What is the temperature in Kelvins?
</span>You already right at this part. Kelvin temperature formula from celsius should be:
K= C+273.15=
<span>K= 27 +273.15 = 300.15
It is important to remember that the formula in this question is using Kelvin unit at temperature, not Celcius or Fahrenheit.
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<span>• Assuming that everything else remains constant, what will happen to the pressure if the temperature decreases to -15 ºC?
</span>In this case, the temperature is decreased from 27C into -15C and you asked the change in the pressure.
Using PV=nRT formula, you can derive that the temperature will be directly related to pressure. If the temperature decreased, the pressure will be decreased too.
<span> If you increase the number of moles to 6 moles, increase temperature to 400K and reduce the volume to 25 L, what will the new pressure be?
</span>PV=nRT
P= nRT/V
P= 6 moles* <span>0.0821 L*atm/(mol*K) * 400K/25L= 7.8816 atm</span>
<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.
Mechanism for oxidation of alkene by KMnO₄ is provided in the attached image:
Answer:
The energy produced equals 140.760 kJ
Explanation:
The relation between power, current and voltage is

Applying the given values in the relation above we get

Now Since 
Again applying the calculated values we get

Replacement I think, hope this helps ;)
Explanation: