<u><em>Answer:</em></u>
- The correct structure of phosphoric acid is A.
<u><em>Explanation</em></u>
- P should form five covalent bonds. In this strcuture P form three single bond with 3-hydroxyl groups while one single bondformed with oxygen. As oxygen will form two bonds , it carry negative charge, while P should form five bond but here it is forming 4 bonds due to this P has positive charge but overall structure contain neutral charge due to cancellation of positive and negative charges. Beside this, there are 3 H, Four O and One P according to formula H3PO4.
0.24J/g*degC * 4.37g * 2.5degC = 2.622J
The 2.5 degC is the difference between 25 and 27.5 deg C.
Answer:
Explanation:
Given parameters:
Mass of aluminium oxide = 3.87g
Mass of water = 5.67g
Unknown:
Limiting reactant = ?
Solution:
The limiting reactant is the reactant in short supply in a chemical reaction. We need to first write the chemical equation and convert the masses given to the number of moles.
Using the number of moles, we can ascertain the limiting reactants;
Al₂O₃ + 3H₂O → 2Al(OH)₃
Number of moles;
Number of moles = 
molar mass of Al₂O₃ = (2x27) + 3(16) = 102g/mole
number of moles =
= 0.04mole
molar mass of H₂O = 2(1) + 16 = 18g/mole
number of moles =
= 0.32mole
From the reaction equation;
1 mole of Al₂O₃ reacted with 3 moles of H₂O
0.04 mole of Al₂O₃ will react with 3 x 0.04 mole = 0.12 mole of H₂O
But we were given 0.32 mole of H₂O and this is in excess of amount required.
This shows that Al₂O₃ is the limiting reactant