Answer:
Density, melting point. and magnetic properties
Explanation:
I can think of three ways.
1. Density
The density of Cu₂S is 5.6 g/cm³; that of CuS is 4.76 g/cm³.
It should be possible to distinguish these even with high school equipment.
2. Melting point
Cu₂S melts at 1130 °C (yellowish-red); CuS decomposes at 500 °C (faint red).
A Bunsen burner can easily reach these temperatures.
3. Magnetic properties
You can use a Gouy balance to measure the magnetic susceptibilities.
In Cu₂S the Cu⁺ ion has a d¹⁰ electron configuration, so all the electrons are paired and the solid is diamagnetic.
In CuS the Cu²⁺ ion has a d⁹ electron configuration, so all there is an unpaired electron and the solid is paramagnetic.
A sample of Cu₂S will be repelled by the magnetic field and show a decrease in weight.
A sample of CuS will be attracted by the magnetic field and show an increase in weight.
In the picture below, you can see the sample partially suspended between the poles of an electromagnet.
The mole<span> is the </span>unit of measurement<span> in the </span>International System of Units<span> (SI) for </span>amount of substance<span>. It is defined as the </span>amount<span> of a </span>chemical substance<span> that contains as many representative particles, e.g., </span>atoms<span>, </span>molecules<span>, </span>ions<span>, </span>electrons<span>, or </span>photons<span>, as there are atoms in 12 </span>grams<span> of </span>carbon-12<span> (</span>12<span>C), the </span>isotope<span> of </span>carbon<span> with </span>relative atomic mass<span> 12 by definition.
so to solve the moles, divide the mass with molar mass
moles = 4177 g / </span><span>133.34 g/mol
moles = 31.33 moles</span>
Answer:
g NaCl = 424.623 g
Explanation:
<em>C</em> NaCl = 3.140 m = 3.140 mol NaCl / Kg solvent
∴ solvent: H2O
∴ mass H2O = 2.314 Kg
mol NaCl:
⇒ mol NaCl = (3.140 mol NaCl/Kg H2O)×(2.314 Kg H2O) = 7.266 mol NaCl
∴ mm NaCl = 58.44 g/mol
⇒ g NaCl = (7.266 mol NaCl)×(58.44 g/mol) = 424.623 g NaCl
Kinetic Energy which relies on an objects mass and velocity and Potential Energy which relies on the height of the object