The most common allotropes are:-
White phosphorus
Red phosphorus
The red one is an intermediate phase between white and violent phosphorus.
Explanation:
Moles of metal,
=
4.86
⋅
g
24.305
⋅
g
⋅
m
o
l
−
1
=
0.200
m
o
l
.
Moles of
H
C
l
=
100
⋅
c
m
−
3
×
2.00
⋅
m
o
l
⋅
d
m
−
3
=
0.200
m
o
l
Clearly, the acid is in deficiency ; i.e. it is the limiting reagent, because the equation above specifies that that 2 equiv of HCl are required for each equiv of metal.
So if
0.200
m
o
l
acid react, then (by the stoichiometry), 1/2 this quantity, i.e.
0.100
m
o
l
of dihydrogen will evolve.
So,
0.100
m
o
l
dihydrogen are evolved; this has a mass of
0.100
⋅
m
o
l
×
2.00
⋅
g
⋅
m
o
l
−
1
=
?
?
g
.
If 1 mol dihydrogen gas occupies
24.5
d
m
3
at room temperature and pressure, what will be the VOLUME of gas evolved?
I believe the correct answer from the choices listed above is option D. Catalysts lower the activation energy of a chemical reaction. It <span>is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction. It provides another pathway for the reaction to occur.</span>
D) energy required to remove a valence electron
Explanation:
The ionization energy is the energy required to remove a valence electron from an element.
Different kinds of atoms bind their valence electrons with different amount of energy.
- To remove the electrons, energy must be supplied to the atom.
- The amount of energy required to remove the an electron in the valence shell is the ionization energy or ionization potential.
- The first ionization energy is the energy needed to remove the most loosely bound electron in an atom in the ground state.
- The ionization energy measures the readiness of an atom to loose electrons.
Learn more:
Ionization energy brainly.com/question/5880605
#learnwithBrainly
Answer:
Techniques and Tests
Qualitative analysis typically measures changes in color, melting point, odor, reactivity, radioactivity, boiling point, bubble production, and precipitation.
