Answer:
As you used two diferent instruments, one is more sensitive than the other.
Explanation:
The sensitivity of an instrument is the minimum amount of magnitude that can be differentiate a measurement system.
In method A, you got 27 cm, so if in method B, you got 27.00, method B is more sensitive. It's like saying that one system measures more than the other
Answer:
16.06 L was the initial volume of the balloon.
Explanation:
Initial moles of freon in ballon = 
Initial volume of freon gas in ballon = 
Moles of freon gas added in the balloon = n = 3.50 mole
Final moles of freon in ballon = 
Final volume of freon gas in ballon = 
Using Avogadro's law:
( at constant pressure and temperature)

16.06 L was the initial volume of the balloon.
You that Mg is the metal if in the periodic table it lands between group 1-12. So yeas Mg is a metal because it lands in group 2.
Answer : The molar mass of an acid is 266.985 g/mole
Explanation : Given,
Mass of an acid (HX) = 4.7 g
Volume of NaOH = 32.6 ml = 0.0326 L
Molarity of NaOH = 0.54 M = 0.54 mole/L
First we have to calculate the moles of NaOH.

Now we have to calculate the moles of an acid.
In the titration, the moles of an acid will be equal to the moles of NaOH.
Moles of an acid = Moles of NaOH = 0.017604 mole
Now we have to calculate the molar mass of and acid.

Now put all the given values in this formula, we get:


Therefore, the molar mass of an acid is 266.985 g/mole