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.
1. L
Number one because the lines match up
Answer:
74.4 ml
Explanation:
C₆H₈O₇(aq) + 3NaHCO₃(s) => Na₃C₆H₅O₃(aq + 3CO₂(g) + 3H₂O(l)
Given 15g = 15g/84g/mol = 0.1786mole Sodium Bicarbonate
From equation stoichiometry 3moles NaHCO₃ is needed for each mole citric acid or, moles of citric acid needed is 1/3 of moles sodium bicarbonate used.
Therefore, for complete reaction of 0.1786 mole NaHCO₃ one would need 1/3 of 0.1786 mole citric acid or 0.0595 mole H-citrate.
The question is now what volume of 0.8M H-citrate solution would contain 0.0595mole of the H-citrate? This can be determined from the equation defining molarity. That is => Molarity = moles solute / Liters of solution
=> Volume (Liters) = moles citric acid / Molarity of citric acid solution
=> Volume needed in liters = 0.0.0595 mole/0.80M = 0.0744 Liters or 74.4 ml
Answer:
A large quantity
Explanation:
A large quantity will take much longer to melt compared to a small quantity of the same matter.
The rate of melt of a substance is particularly a function of the nature of the substance and the amount of energy supplied to it.
If we assume that we are dealing with different quantities of the same substance, then the one that has more mass will melt faster because less energy would be required to change its state.
A large quantity of matter will take more time to melt.
137 K
The volume is constant, so you can use <em>Gay-Lussac’s Pressure-Temperature Law </em>to calculate the new temperature (you don’t have to use the number of moles).
P1/T1 = P2/T2
Solve for T2: T2= T1 x P2/P1
P1 = 1.83 atm; T1 = 122 K
P2 = 2.05 atm; T2 = ?
∴ T2 = 122 K x (2.05 atm)/(1.83 atm) = 137 K
This result makes sense. Temperature is directly proportional to pressure. You increased the pressure by about 10 %, so the temperature increased by about 10 %.
