Answer:
2Ag + H2O -----> Ag2O + 2H
Explanation:
2Ag + H2O -----> Ag2O + 2H is the equation of the reaction between metal and steam. Silver reacts with water (steam) forming silver oxide and hydrogen gas. When the metals react with steam it produces the solid metal oxide and hydrogen gas. On the surface o metals, a protective layer of aluminium oxide is formed that keeps water away from the metal so we can say that silver oxide and hydrogen are formed from the reaction of silver metal and steam.
So half life is the time taken for a sample to decay to half its original mass, its a constant and applies to any original mass, it could be 5g or 1kg, it will take the same amount of time for the original mass to half. In this case the half life is 3 days.
After 3 days the sample will be at half its original mass, now 50g.
Now we can treat the 50g as if its a new sample. After another 3 days (6 days in total) there will be half of 50g left, = 25g.
Answer:
The standard enthalpy of formation of this isomer of octane is -220.1 kJ/mol
Explanation:
Step 1: Data given
The combustion reaction of octane produces 5104.1 kJ per mol octane
Step 2: The balanced equation
C8H18(g) + 12.5 O2 ⟶ 8CO2 (g) + 9 H2O (g) ∆H°rxn = -5104.1 kJ/mol
Step 3:
∆H°rxn = ∆H°f of products minus the ∆H° of reactants
∆H°rxn = ∆H°f products - [∆H°f reactants]
-5104.1 kJ/mol = (8*∆H°fCO2 + 9*∆H°fH20) - (∆H°fC8H18 + 12.5∆H°fO2)
∆H°f C8H18 = ∆H°f 8CO2 + ∆H°f 9H2O+ 5104.1 kJ/mol
∆H°f C8H18 = 8 * (-393.5 kJ)/mol + 9 * (-241.8 kJ/mol)] + 5104.1 kJ
/mol
∆H°f C8H18 = -220.1 kJ/mol
The standard enthalpy of formation of this isomer of octane is -220.1 kJ/mol
B. A gram would have a lot more molecules of propane than a mole
Answer:
The mass of the jar and contents remained the same after the metal was burned.
Explanation:
My prediction about the experimental results is that the mass of the jar and contents remained the same after the metal was burned in the jar.
This is compliance with the law of conservation of mass which states that in a chemical reaction, matter is neither created nor destroyed by bonds are rearranged for new compounds to form.
- In compliance with this law, it is expected that the mass of the jar and its content will remain the same before and after the reaction.
- No new material was added and no material was removed from the jar.
