The visual or mathematical representation of an object system or concept is known as a model. Hope this helps and mark as brainliest!
Answer:
D. They involve changes in energy.
The last one
Explanation:
have a good day
Assuming that there is missing information in this question I’m just going to go ahead and say that it’s lower.
HNO3 (nitric acid) is a very strong acid which should be found on the lower end of the pH scale. While water, on the other hand, is neutral and found at a pH of 7.
So if you add one drop of a strong acid into a neutral solution of 100ml let’s say, one can assume that the pH of that solution is now very low and probably found between 1-3 on a pH scale.
Reminder:
-Acids are found between 1-6 on the pH scale. The lower the number the stronger the acid
-Bases are found between 8-14 on the pH scale. The higher the number the stronger the base
Answer:
900g
Explanation:
Given parameters:
Number of moles of Sc = 20moles
Unknown:
Mass of Sc = ?
Solution:
To find the mass of the scandium given, we use the expression below:
Mass = Number of moles x molar mass
Molar mass of Sc = 45g/mol
So;
Mass of Sc = 20 x 45 = 900g
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.
