Answer:

Explanation:
= Concentration of stock solution
= Concentration of solution
= Volume of stock solution = 19 mL
= Volume of solution = 0.31 L= 310 mL
We have the relation


The concentration of the diluted solution will be 0.613 times the concentration of the stock solution.
Answer:
b) 2.0 mol
Explanation:
Given data:
Number of moles of Ca needed = ?
Number of moles of water present = 4.0 mol
Solution:
Chemical equation:
Ca + 2H₂O → Ca(OH)₂ + H₂
now we will compare the moles of Ca and H₂O .
H₂O : Ca
2 : 1
4.0 : 1/2×4.0 = 2.0 mol
Thus, 2 moles of Ca are needed.
Answer:
a)
b)
Explanation:
a) The reaction:

The free-energy expression:

![E=E_{red}-E_{ox]](https://tex.z-dn.net/?f=E%3DE_%7Bred%7D-E_%7Box%5D)
The element wich is reduced is the Fe and the one that oxidates is the Mg:

The electrons transfered (n) in this reaction are 2, so:


b) If you have values of enthalpy and enthropy you can calculate the free-energy by:

with T in Kelvin


Answer:
Shivering.
Explanation:
Homeostasis is the bodies need to keep things at a normal. When you are cold you shiver to produce body heat and get back to normal