N2 + 3 H2 >> 2 NH3
moles NH3 = 11.50 g /17.0307 g/mol=0.6753
the ratio between H2 and NH3 is 3 : 2
moles H2 needed = 0.6753 x 3/2 =1.013
mass H2 = 1.013 mol x 2.106 g/mol=2.042 g
Answer:
56.69905
Explanation:
The conversion factor from pounds to kilograms is 0.45359237, which means that 1 pound is equal to 0.45359237 kilograms.
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.
Answer:
Within a group trend
Explanation:
The atomic radius of atoms generally increases from top to bottom within a group trend. As the atomic number increases down a group, there is again an increase in the positive nuclear charge. As the atomic number increases within a period, the atomic radius decreases.
Answer:
I₂ + H₂O --------→ HI + HIO
Explanation:
Iodine is not fully dissolve in water but only dissolve up to some extent.
When iodine was mixed with water it give mixture of two products.
- Hydrogen iodide or hydroiodic acid (HI)
- Hypoiodous acid (HIO)
So the balance reaction is as under
I₂ + H₂O --------→ HI + HIO
All the reactant are one mole and one one mole of each product produced in the shown reaction.
This is a reversible reaction and only 0.05% of Iodine molecule react with water and the other Iodine molecule remain in water unreacted.
