Processes in which matter changes between liquid and solid states are freezing and melting. Processes in which matter changes between liquid and gaseous states are vaporization, evaporation, and condensation. Processes in which matter changes between solid and gaseous states are sublimation and deposition.
I a chemical reaction, we have the reactants in the left part,followed by an arrow and then the products.
So, the reactants are the two that are in the left part of the equation:
Sodium hydroxide and Hydrochloric acid
Answer:
B. - 210 kJ
Explanation:
<em>∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.</em>
- The bond formation in the products releases energy (exothermic).
- The bond breaking in the reactants requires energy (endothermic).
The products:
- H₂O contains 2 O-H (- 459 kJ/mol) bonds.
- O₂ contain 1 O=O (- 494 kJ/mol) bond.
The reactants:
- H₂O₂ contain 2 O–H (459 kJ/mol) bonds and 1 O–O (142 kJ/mol) bond.
∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.
<em>∴ ΔHrxn = [2 (2 x (O–H bond energy) + (1 x (O=O bond energy)] - 2 [(2 x (O–H bond energy) + (1 x (O–O bond energy)] </em>= [2 (2 x - 459 kJ/mol) + (1 x - 494 kJ/mol)] - 2 [(2 x 459 kJ/mol) + (1 x 142 kJ/mol)] = (- 2330 kJ) + (2120 kJ) = <em>- 210 kJ.</em>
This is because the minerals that make up the rocks form only at certain temperatures and pressures. At high temperatures or pressures, the elements will rearrange their crystal structure to form a different mineral. Graphite and diamond are two minerals that are both made entirely out of carbon.
Answer:
The answer to your question is:
Explanation:
2.45 g of Phosphorus
MW P = 31 g
MW P2O5 = 2(31) + 5(16) = 142 g
From the balance reaction
4 P ⇒ 2 P2O5
Then 4(31) g P ⇒ 2 (142) g P2O5
124g of P ⇒ 284 g of P2O5 Rule of three
2.45g P ⇒ x
x = 2.45 x 284/124 = 695.8/124 = 5.61 g of P2O5
