The answer would be .5 mols because you take the total amount of grams, which is 20, and you had up the molar mass of sodium hydroxide, which would be 40. After you have this you would set this up as a stochiometry equation. With 1 mol on top you dived 20/40 to cancel out your grams. This leaves you with .5 mols
Answer: The percentage by mass of sulphur in
is 9.36%
Explanation:
Mass percent of an element is the ratio of mass of that element by the total mass expressed in terms of percentage.

Given: mass of sulphur = 32 g/mol
mass of
= 342 g/mol
Putting in the values we get:

The percentage by mass of sulphur in
is 9.36%
Answer:
4121 years
Explanation:
From;
0.693/t1/2 = 2.303/t log No/N
t1/2= half life of the carbon-14
No= count rate of the living tissue
N= count rate of the sample
t = age of the sample
0.693/5730 =2.303/t log (13.5/8.2)
1.21 * 10^-4 = 2.303/t * 0.2165
1.21 * 10^-4 = 0.4986/t
t = 0.4986/1.21 * 10^-4
t = 4121 years
Answer:
I think it's B " Constraints are more important than criteria ".
Less water = less weight to make it rise
More water = more weight to make it dive