The given question is incomplete. The complete question is as follows.
A solution contains an unknown mass of dissolved barium ions. When sodium sulfate is added to the solution, a white precipitate forms. The precipitate is filtered and dried and then found to have a mass of 212 mg. What mass of barium was in the original solution? (Assume that all of the barium was precipitated out of solution by the reaction.)
Explanation:
When 
and 
are added then white precipitate forms. And, reaction equation for this is as follows.
It is given that mass (m) is 212 mg or 0.212 g (as 1 g = 1000 mg). Molecular weight of 
is 233.43.
Now, we will calculate the number of moles as follows.
No. of moles = mass × M.W
= 
= 0.00091 mol of
Hence, it means that 0.00091 mol of . Now, we will calculate the mass as follows.
Mass = moles × MW
= 
= 0.124 grams or 124 mg of barium
Thus, we can conclude that mass of barium into the original solution is 124 mg.
Answer:
Newton's third law
Explanation:
every action has an equal and opposite reaction.
Answer:
a. 0.5dm³
b. 5x10⁻³dm³
Explanation:
a. A solution that is 4mol/dm³ contains 4 moles in 1dm³. The volume that contains 2 moles is:
2 moles * (1dm³ / 4mol) =
<h3>0.5dm³</h3><h3 />
b. And for the 6 mol/dm³ containing 0.03moles:
0.03 moles * (1dm³ / 6mol) =
<h3>5x10⁻³dm³</h3>
Answer:
Molecules start out unevenly distributed and end up evenly distributed.
Explanation:
Diffusion is the process by which molecules of a substance move from a region of higher concentration to a region of lower concentration until equilibrium is attained.
Molecules start out unevenly distributed and end up evenly distributed in a particular medium. Diffusion occurs due to the particulate nature of matter. When the particles that make up a substance are concentrated at a point, the collide more often with one another causing each molecule to spread out in order to occupy all the available space.
Diffusion occurs in gases, liquids and solids but occurs fastest in gases. Diffusion can be observed for example, in the spread of the smell of a dead rat from one point in a room to every part of the room.
Answer:
Total mass of original sample = 0.38 g
Explanation:
Percentage of chloride = 74.5%
Mass of AgCl precipitate = 1.115 g
Mass of original sample = ?
Solution:
Mass of chloride:
1.115 g/ 143.3 g/mol × 35.5 g/mol
0.0078 g × 35.5 = 0.28 g
Total mass of compound:
Total mass = mass of chloride / %of Cl × 100%
Total mass = 0.28 g/ 74.5% × 100%
Total mass = 0.0038 g× 100
Total mass = 0.38 g
