Answer:
a) 
b) 
c) 
Explanation:
Hello,
a) In this case, the given height in cm is:

And the radius in cm is:

Thus, the volume in cubic centimeters which is also equal in mL (1cm³=mL) is:

b) In this case, the given height in mm is:

And the radius in mm is:

Thus, the volume in cubic millimeters is:

c) Finally, since 1000 mL equal 1 L, the required density in g/L turns out:

Best regards.
Less dense than the liquid
In a titration, for an acid to neutralize a base, at the equivalence point, there should be an equal number of moles of H+ and OH-.
Moles of OH- can be found by multiplying the concentration of the base by the volume. (You will need to keep in mind the stoichimetric coefficients if the strong base is Ca(OH)₂, Ba(OH)₂, or Sr(OH)₂.
Moles of OH- = moles of H+
(0.253 M) * 0.005 L = 0.01000 L * c
c = 0.1265 M
The concentration of HBr is 0.127 M.
There are 3 significant figures. Significant numbers are the numbers that build up your total number. 1-9 always count, 0 only counts if it’s after another number. For example: 0,901 has 3 significant numbers as does 0,910. 9,10 also has 3. 0,09 has just 1.