Answer:
Here's what I get
Explanation:
You want to dilute the original solution by a factor of 25 in two steps, so you could dilute it by a factor of 5 in the first step, then dilute the new solution by another factor of 5.
A. First dilution
Use a 10 mL pipet to transfer 10 mL of the original solution to a 50 mL volumetric flask. Make up to the mark with distilled water. Shake well to mix.
Use the dilution formula to calculate the new concentration.

B. Second dilution
Repeat Step 1, using the 0.003 970 mol·L⁻¹ solution.

3. Check:
Compare the final concentration with the original

Answer: A
Explanation: the first answer is more reasonable than the rest of them , hope this helped
Answer:
Oh it is convention
Explanation:
because the heat transfer is through fluids
Answer:
13.4mol of Mg
Explanation:
Given parameters:
Mass of magnesium = 321g
Unknown:
Number of moles = ?
Solution:
The number of moles of a substance is given as;
Number of moles =
Molar mass of Mg = 24g/mol
Insert the parameters and solve;
Number of moles =
= 13.4mol of Mg