Answer:
Potassium permanganate has a molar mass of 158.04 g/mol. This figure is obtained by adding the individual molar masses of <em><u>four oxygen atoms</u></em>, <em><u>one manganese atom</u></em> and <em><u>one potassium atom</u></em>
Explanation:
Magnesium(?)
<span>2 HCl + Mg ? MgCl2 + H2</span>
I believe visible light is made from photons
Answer:
4 moles of neon
Explanation:
Given data:
Number of moles of neon = ?
Number of atoms of neon = 2.4×10²⁴ atoms
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For given neon atoms:
1 mol = 6.022 × 10²³ atoms
2.4×10²⁴ atoms × 1 mol / 6.022 × 10²³ atoms
0.4×10¹ mol = 4 mol
Answer : At constant pressure work is done by the system on the surroundings.
Explanation :
Work done : Any quantity that flows across the boundary of a system during a change in its state and it completely convertible into the lifting of a weight in the surroundings.
Formula for work done is:

Sign convention :
- When volume expand then system work that means work done by the system.
w = (-ve)
- When volume compress then surrounding work that means work done on the system.
w = (+ve)
The given reaction is:

This is a evaporation process in which phase changes from liquid state to gaseous state at constant temperature.
At constant pressure, work depends only on volume.
In evaporation process, the volume expand that means work is done by the system on the surroundings.
Sign convention is, w = (-ve)
Thus, at constant pressure work is done by the system on the surroundings.