<span>The pressure inside a coke bottle is really high. This helps keep the soda carbonated. That is, the additional pressure at the surface of the liquid inside the bottle forces the bubbles to stay dissolved within the soda. </span><span>When the coke is opened, there is suddenly a great pressure differential. The initial loud hiss that is heard is this pressure differential equalizing itself. All of the additional pressure found within the bottle pushes gas out of the bottle until the pressure inside the bottle is the same as the pressure outside the bottle. </span><span>However, once this occurs, the pressure inside the bottle is much lower and the gas bubbles that had previously been dissolved into the soda have nothing holding them in the liquid anymore so they start rising out of the liquid. As they reach the surface, they pop and force small explosions of soda. These explosions are the source of the popping and hissing that continues while the soda is opened to the outside air. Of course, after a while, the soda will become "flat" when the only gas left dissolved in the liquid will be the gas that is held back by the relatively weak atmospheric pressure.</span>
The concentration of the HCl solution is 0.047 M.
Explanation:
Data given about acid and base:
volume of acid Vacid = 46.9 ml
molarity of acid =?
volume of the base (NaOH) = 16.4 ml
molarity of the base = 0.135 M
To know the concentration of the acid in this reaction, the formula used in titration is used. It is
Macid X Vacid = Mbase X Vbase
the formula is rewritten as:
Macid = 
putting the values in the equation:
Macid = 
= 0.047 M
the concentration of the acid i.e HCl in the solution is of 0.047 M.
This separation technique is a 4-step procedure. First, add H₂SO₄ to the solution. Because of common ion effect, BaSO₄ will not react, only Mg(OH)₂.
Mg(OH)₂ + H₂SO₄ → MgSO₄ + 2 H₂O
The aqueous solution will now contain MgSO₄ and BaSO₄. Unlike BaSO₄, MgSO₄ is soluble in water. So, you filter out the solution. You can set aside the BaSO₄ on the filter paper. To retrieve Mg(OH)₂, add NaOH.
MgSO₄ + 2 NaOH = Mg(OH)₂ + Na₂SO₄
Na₂SO₄ is soluble in water, while Mg(OH)₂ is not. Filter this solution again. The Mg(OH)₂ is retrieved in solid form on the filter paper.
I believe the answer is 1-Water :)