4. A
because PbCl2 is an ionic compound and it's solid, so it's a substance.
It cannot be mixture, because it's a pure molecule.
5. D
despite that both substances are gases, colorless they are different molecules, so they should have different either chemical and physical properties
6. C
this substance made from W atoms and others are made from molecules
Answer:
the same
Explanation:
due to the law of conservation of mass, the mass will not change
Volume of the gas is 525 L.
<u>Explanation:</u>
It is given that the volume of the gas divided by the temperature is 1.75.
V/T = 1.75
As per the Charles law, volume is proportional to the temperature.
V ∝ T
V/T = constant
Now we have to find V, and T is given as 300 K.
So plugin the values as,
V/300 = 1.75
Rearranging the equation to get V as,
V = 1.75×300
= 525 L
7 becuse it splits in half