Correct Answer: option 1 i.e. C
Reason:
The the compound of interest i.e. XCl4, since there are 4 Cl atoms bonded to X. This signifies that the valency of X is 4.
There atomic number of C is 6. It's electronic configuration is giving by 1s2 2s2 2p2. Thus, there are 4 electrons in valence shell of C. This signifies that valency of C is 4. Hence the compound present in present case is CCl4.
Sodium/Atomic number
11
Gold/Atomic number
79
Potassium/Atomic number
19
Silicon/Atomic number
14
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:- New pressure is 0.942 atm.
Solution:- The volume of the glass bottle would remain constant here and the pressure will change with the temperature.
Pressure is directly proportional to the kelvin temperature. The equation used here is:

Where,
and
are initial and final temperatures,
and
are initial and final pressures.
= 20.3 + 273.15 = 293.45 K
= -2.0 + 273.15 = 271.15 K
= 1.02 atm
= ?
Let's plug in the values in the equation and solve it for final pressure.


= 0.942 atm
So, the new pressure of the jar is 0.942 atm.
Answer:
lens are the answers, I hope it is right