When other scientists repeat experiments and come up with the same results it validates it and show that the answers are true
Net ionic equation
Cu²⁺(aq)+S²⁻(aq)⇒CuS(s)
<h3>Further explanation</h3>
Double-Replacement reactions. Happens if there is an ion exchange between two ion compounds in the reactant to form two new ion compounds in the product
In the ion equation, there is a spectator ion that is the ion which does not react because it is present before and after the reaction
When these ions are removed, the ionic equation is called the net ionic equation
For gases and solids including water (H₂O) can be written as an ionized molecule
Reaction
CuSO₄(aq)+Na₂S(aq)⇒CuS(s)+Na₂SO₄
ionic equation
Cu²⁺(aq)+SO₄²⁻(aq)+2Na⁺(aq)+S²⁻(aq)⇒CuS(s)+2Na⁺(aq+SO₄²⁻(aq)
spectator ions : 2Na⁺ and SO₄²⁻
Net ionic equation
Cu²⁺(aq)+S²⁻(aq)⇒CuS(s)
Answer:
CHCI₃
Explanation:
Chloroform, IUPAC name, trichloromethane, is organic compound with the molecular formula CHCl₃. It is colorless and sweet-smelling liquid having high density which is produced on a large scale precursor of PTFE , and for various refrigerants .
Chloroform , is a powerful euphoriant , anxiolytic , anesthetic and sedative when inhaled or ingested .
Answer:
3) The calculated density would be high, because the volume would be incorrectly measured low.
Explanation:
Density is defined as mass per unit volume. It means the density is inversely proportional to the volume.
A solid with a hollow center will have high volume due to air inside the hollow area that will lead to low density.
But the error in the calculation of density is that the "density would be high, because the volume would be incorrectly measured low."
Hence, the correct answer is "3)"
Answer: C. ethanol
The enthalpy of combustion is the amount of heat produced when one mole of ethanol undergoes complete combustion at 25 ° C and 1 atmosphere pressure, yielding products also at 25 ° C and 1 atm.
<u>The enthalpy of combustion of the unknown compound is</u>
ΔH = - 320 kJ / 0.25 mol = - 1280 kJ / mol
<u>To choose a probable compound according to this combustion enthalpy, we must evaluate the deviation in relation to the values reported in the literature for the three probable compounds</u> (methane, ethylene and ethanol). The deviation (e%) will be calculated according to the following equation,
e% = ( | ΔHx - ΔH | / ΔHx ) x 100%
where ΔHx is the enthalpy of combustion of the probable compound.
The following table shows the combustion enthalpies of the probable compounds and their deviation in relation to the enthalpy of ΔH = - 1280 kJ / mol
Compound Enthalpy of combustion (kJ/mol) Deviation
Methane - 890.7 43.8%
Ehylene -1411.2 9.3%
Ethanol -1368.6 6.5%
According to the previous table, we can say that the most probable compound is ethanol, since it has the smallest deviation in relation to the experimental enthalpy value of combustion.
