Answer:
The correct answer is "They can be separated by physical processes"
Explanation:
The definition of Mixtures is <em>the blending of two or more dissimilar substances</em>.
Mixtures can be divided into those that are homogeneous or heterogeneous meaning that they can be distributed evenly or can't be distributed evenly.
I honestly have no clue on this one
Answer:
Na2S, (NH4)3PO4
Explanation:
We can decide what compounds are soluble by considering the solubility rules that apply.
CdCO3 is not soluble in water because all carbonates are insoluble except those of ammonium, sodium and potassium.
Na2S is soluble in water because all sulphides are insoluble except those of sodium, potassium and ammonium.
PbSO4 is insoluble in water because all sulphates are soluble except those of lead and barium. The sulphate of calcium is only slightly soluble in water.
(NH4)3PO4 is soluble in water because all phosphates are insoluble except those of sodium, potassium and ammonium.
Hg2Cl2 is insoluble in water because all chlorides are soluble except those of lead, mercury II and silver.
We are given the molar concentration of an aqueous solution of weak acid and the pH ofthe solution, and we are asked to determine the value of Ka for the acid.
The first step in solving any equilibrium problem is to write the equation for the equilibriumreaction. The ionization of benzoic acid can be written as seen in the attached image (1).
The equilibrium-constant expression is the equation number (2)
From the measured pH, we can calculate pH as seen in equation (3)
To determine the concentrations of the species involved in the equilibrium, we imagine that thesolution is initially 0.10 M in HCOOH molecules. We then consider the ionization of the acidinto H+ and HCOO-. For each HCOOH molecule that ionizes, one H+ ion and one HCOO- ionare produced in solution. Because the pH measurement indicates that [H+] = 1x 10^-4 M atequilibrium, we can construct the following table as seen in the equation number (4)
To find the value of Ka, please see equation (5):
We can now insert the equilibrium concentrations into the expression for Ka as seen in equation (6)
Therefore, 2.58x10^-4 M is the concentration of benzoic acid to have a pH of 4.0
Note that
The heating value of standard coal is about 30,080 kJ/kg
1 L of water has a mass of 1.0 kg
The mass of 15 L of water = 15 kg.
The latent heat of vaporization of water is about 2260 kJ/kg,
The energy required to boil 15 L of water is
(2260 kJ/kg)*(15 kg) = 33900 kJ
The mass of coal required to provide this energy is
(33900 kJ)/(30080 kJ/kg) = 1.127 kg
Because 1 kg = 2.205 lb, the mass of coal required is
(1.127 kg)*(2.205 lb/kg) = 2.485 lb
Answer: 2.49 lb (nearest hundredth)