Answer:
There was a change in temperature on the surface you were walking on. It is possible that "you" were walking on cool, wet sand and when your parents said it was time to leave, you ran barefoot towards the parking lot (away from the sand) and got a burning coal sensation on your feet.
Explanation:
Hydrophobic in simple terms is the "fear" of water.
In chemistry, Ionic salts are technically hydrophilic as they will dissolve in water.
most fats and oils or triesters won't why?
salts are made from ions and their structure contain polar bonds Na+ and Cl-
Fats and oils tend to not have these.
Fats and oils contain many carbon covalent bonds which are non-polar which tend to make the molecule non-polar as a whole, therefore, it can't dissolve in water and is said to be hydrophobic.
Hope that heps :)
NB included a diagram to help.
Given teh equation adn the heat of reaction, reaction 2's heat of reaction can be obtained by simply multiplying teh heat of reaction of 1 by 3. The final answer is -6129 kJ.
Answer:
endothermic
Explanation:
It is endothermic since it absorbs heat. If the reaction RELEASED heat (exothermic) the "+ heat" would be on the right side of the equation.
Answer : The approximate relation Celsius = 1/2 Fahrenheit is a better approximation at higher temperatures
Explanation :
The formula for Celsius to Fahrenheit conversion is

At lower temperature the value that needs to be subtracted (32) is large enough as a result the approximation "celsius = 1/2 fahrenheit " does not seem valid.
For example, 50 F is 10°C.

This is almost 1/5 of Fahrenheit temperature.
But at higher temperatures , the value becomes insignificant and also the ratio 5/9 tend to be equal to 0.5.
For example, 2000 F is 1093°C

This is almost half of Fahrenheit temperature.
Therefore , the approximate relation Celsius = 1/2 Fahrenheit is a better approximation at higher temperatures