if we did not use an excess of the BaCl2 solution it would decrease the mass percentage of sulfate in the unknown sample.
The net precipitation equation would be.
Ba2+(aq) + SO42-(aq) → BaSO4(s)
If BaCl2 (Ba2+) is not taken in excess then the precipitation would not be completed as some of the sulfate ions would still be remaining in the solution. This would decrease the mass percentage of sulfate in the unknown sample.
If some tiny pieces of filter paper still remained mixed with the precipitate(BaSO4) then the mass of sulfate would increase and it gives a high mass percentage of the sulfate.
mass percentage of sulfate = (mass of sulfate/mass of sample)*100
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Answer is "C".
<em><u>Explanation
</u></em>
Single replacement reaction is a type of reaction which one reactant reacts with another and makes a product by replacing one element by another.
Mg (Magnesium) reacts with Al₂O₃ (Aluminium oxide) and produces MgO (Magnesium oxide) and Al (Aluminium) as products. Here Al is replaced by Mg. Reaction is
Mg + Al₂O₃ → MgO + Al
To balance the reaction equation, both left and right hand sides should have same number of atoms in each element.
Here,
<em>Left Hand Side has </em> <em>Right Hand Side has</em>
Mg = 1 atom Mg = 1 atom
Al = 2 atom Al = 1 atom
O = 3 atom O = 1 atom
First step : balance the O atoms in both sides. To do that "3" should be added before MgO.
Second step : After balancing O atoms, there will be 3 Mg atoms in right hand side. Hence to balance Mg atoms again "3" should be added before Mg in left hand side
Third step : as the final step balance the Al atoms by adding "2" before Al in the right hand side.
Then final balanced equation should be
3Mg + Al₂O₃ → 3MgO + 2Al
Answer:
D
Explanation:
Without gravity, any object wont go to the ground, and without a magnetic field, a compass cant be used for navigation.
Answer:
56.2÷6.02×10^23
=9.34×10^23
Explanation:
Divide the given mass of the atom by the mass of an Atom (the avogadro's constant) to find the number of atoms in the given mass.
Answer: HCl
Explanation:
calcium carbonate dissolves in HCl acid producing CO 2 gas. It will not dissolve in pure water. The Ksp for calcium carbonate in water is 3.4 x 10-9 moldm-3 which is very low. What takes place here is actually a chemical reaction:
CaCO 3 (s) + 2HCl(aq) → CaCl 2 (aq) + H 2CO 3(aq)
This reaction accounts for the solubility of the Calcium carbonate in HCl and not in pure water.
