B. it means the compound is dissolved in water
Answer:
Filtration
Explanation:
Filtration is a physical separation technique that is used to separate solids from liquids or gases. The process involves the use of a filter which allows just the liquid to pass through.
In this case, the coffee beans is the solid and the boiling water is the liquid. The special piece of paper is the medium (filter) through which the coffee is collected.
The coffee coming through the special piece of paper (filter) is called a filtrate.
Filtration is used in the preparation of the cup of coffee.
It describes how, when particles/mc/elements react, despite forming different substances the mass is neither created nor destroyed but only converted.
Answer:
crystalline solid
Most ionic compounds exist in crystalline solid form especially at room temperature.
Explanation:
The combustion of naphthalene is given as:
C10H8 (s) + 12 O2 (g) --> 10CO2 (g) + 4 H2O (l)
Enthalpy of combustion ΔH = -5157 kJ/mol
Now, the enthalpy change of a reaction is given
ΔH = ∑nΔHf (products) - ∑nΔHf (reactants)
where n = number of moles
ΔHf = enthalpy of formation
Therefore,
ΔH = [10*ΔHf(CO2) + 4*ΔHf(H2O)] - [1*ΔHf(C10H8) + 12*O2]
-5157 = [10*(-393.5) + 4*(285.83)] - [ΔHf(C10H8) + 12*(0)]
ΔHf(C10H8) = 78.68 kJ/mol
