Answer:
The Nitric Acid Test
Explanation:
The Nitric Acid Test is used to check if silver is pure or plated. To do so, file a small part of the item in a discreet area where it cannot be seen. Apply a few drops of nitric acid. If the area turns into creamy white, the silver is pure or sterling. If green, it is probably fake or silver-plated.
The enthalpy change (ΔH) for the neutralization of 0.1 moles of 1.0 M NaOH with 0.1 moles of 1.0 M HCl in a coffee-cup calorimeter is approximately 28.05 kJ/mol.
To calculate the enthalpy change (ΔH) for the neutralization of HCl by NaOH, you can use the equation:
ΔH = q / moles of limiting reactant
First, let's find the moles of the reactants. We have 100.0 mL of 1.0 M NaOH and 100.0 mL of 1.0 M HCl. Since we know the volumes and concentrations, you can find the moles of each reactant using the formula:
moles = (volume in L) × (concentration in mol/L)
For NaOH:
moles of NaOH = (100.0 mL / 1000 mL/L) × 1.0 mol/L = 0.1 moles
For HCl:
moles of HCl = (100.0 mL / 1000 mL/L) × 1.0 mol/L = 0.1 moles
Now, you need to determine the limiting reactant. The balanced chemical equation for the neutralization of HCl by NaOH is:
NaOH + HCl → NaCl + H₂O
The stoichiometric ratio of NaOH to HCl is 1:1, which means they react in a 1:1 ratio. Since both reactants have 0.1 moles, neither is in excess. Therefore, the reactant that limits the reaction is the one that is present in the smaller amount, which is NaOH in this case.
Now, calculate the heat absorbed or released (q) using the equation:
q = mΔTC
Where:
m is the mass (in grams) of the solution, which we can calculate using the density of 1.0 g/cm³ and the volume (in mL).
ΔT is the change in temperature.
C is the specific heat capacity (given as 4.18 J/g°C).
For the volume of 100.0 mL, the mass is 100.0 g (since 100.0 mL = 100.0 g, given the density is 1.0 g/cm³).
ΔT = Final temperature - Initial temperature
ΔT = 31.38°C - 24.68°C = 6.70°C
Now, calculate q for the reaction:
q = 100.0 g × 6.70°C × 4.18 J/g°C = 2804.76 J
Finally, calculate the enthalpy change (ΔH) by dividing q by the moles of the limiting reactant:
ΔH = 2804.76 J / 0.1 moles = 28047.6 J/mol
Since the enthalpy change is typically expressed in kJ/mol, divide by 1000 to convert J to kJ:
ΔH = 28.05 kJ/mol
So, the enthalpy change for the neutralization of HCl by NaOH is approximately 28.05 kJ/mol.
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Answer:
-0.6⁰c
Explanation:
find the solution below
B) A unit made up of several atoms.
C) A unit made up of several molecules.
The term monomer refers to:
a unit made up of several atoms
Explanation:
A monomer is a molecule that "can support polymerization whereby providing constitutional units to the fundamental structure of a macromolecule". Large quantities of monomers combine to form polymers in a method called polymerization.
Answer:
The reaction of an aqueous hydrochloric acid solution with an aqueous sodium hydroxide solution is represented by the neutralization chemical equation:
HCl(aq) + NaOH(aq) --> NaCl(aq) + H2O(l) + Energy
Explanation:
This is called a neutralization reaction, which is a reaction in which an acid and a base react to form water and a salt. This reaction involves the combination of H+ ions and OH- ions to generate water. pH equal to 7 is a neutralization of a strong acid and strong base. The neutralization of a strong acid and weak base will have a pH of less than 7, and conversely, the resulting pH when a strong base neutralizes a weak acid will be greater than 7.
When a solution is neutralized, it means that salts are formed from equal weights of acid and base. The amount of acid needed is the amount that would give one mole of protons (H+) and the amount of base needed is the amount that would give one mole of (OH-).
The production of sodium chloride and water is the indication that reaction took place.
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B) atomic number
C) number of protons
D) number of electrons
The quantity that can vary among atoms of the same element is the mass number, which represents the sum of the number of protons and neutrons in an atom.
The quantity that can vary among atoms of the same element is the mass number. The mass number represents the sum of the number of protons and neutrons in an atom. While the atomic number (which represents the number of protons) remains constant for atoms of the same element, the number of neutrons can vary, resulting in different mass numbers for atoms of the same element.
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