Answer:
Macroscopic observation
Explanation:
The observation is macroscopic because you could observe the transformation with the naked eye.
Answer:
0.67 mole/litre
Explanation:
the molarity equall no. of moles ÷ volume of sol.
Enthalpy of formation is calculated by subtracting the total enthalpy of formation of the reactants from those of the products. This is called the HESS' LAW.
ΔHrxn = ΔH(products) - ΔH(reactants)
Since the enthalpies are not listed in this item, from reliable sources, the obtained enthalpies of formation are written below.
ΔH(C2H5OH) = -276 kJ/mol
ΔH(O2) = 0 (because O2 is a pure substance)
ΔH(CO2) = -393.5 kJ/mol
ΔH(H2O) = -285.5 kJ/mol
Using the equation above,
ΔHrxn = (2)(-393.5 kJ/mol) + (3)(-285.5 kJ/mol) - (-276 kJ/mol)
ΔHrxn = -1367.5 kJ/mol
<em>Answer: -1367.5 kJ/mol</em>
Green colored precipitate of iron (||) hydroxide
Answer:
the third option
Explanation:
The circuit is incomplete and broken, and the lights in the circuit do not shine.
An open circuit means an incomplete circuit.
The first option is wrong since the lights do not shine in an open circuit.
The second option is wrong since an open circuit is incomplete.
The fourth option is also wrong since an open circuit is broken or incomplete.
∴ The third option is correct.