Answer:
C. fluorine (F) and chlorine (Cl)
D. arsenic (As) and antimony (Sb)
Explanation:
In the periodic table , all the elements are arranged according to the atomic number ,
and the elements are placed in groups and periods ,
The elements with similar chemical and physical properties are placed in a common group .
The elements present in the same group have the same number of valence electrons in the valence shell .
Hence , from the given options ,
fluorine (F) and chlorine (Cl) belongs to group 17 with 7 valence electrons in the outermost shell .
arsenic (As) and antimony (Sb) belong to group 15 with 3 valence electrons in the outermost shell .
The percentage of CO2 increased 48 percent. Hope this helped!
Answer:
La glucosa y la galactosa son estereoisómeros (tienen átomos unidos en el mismo orden, pero dispuestos de forma diferente en el espacio). ... La fructosa es un isómero estructural de glucosa y galactosa (tiene los mismos átomos, pero unidos en un orden diferente).
Explanation:
Answer:
235 g
Explanation:
From the question;
- Volume is 400.0 mL
- Molarity of a solution is 4.25 M
We need to determine the mass of the solute K₂CO₃,
we know that;
Molarity = Number of moles ÷ Volume
Therefore;
First we determine the number of moles of the solute;
Moles = Molarity × volume
Moles of K₂CO₃ = 4.25 M × 0.4 L
= 1.7 moles
Secondly, we determine the mass of K₂CO₃,
We know that;
Mass = Moles × Molar mass
Molar mass of K₂CO₃, is 138.205 g/mol
Therefore;
Mass = 1.7 moles × 138.205 g/mol
= 234.9485 g
= 235 g
Thus, the mass of K₂CO₃ needed is 235 g
To solve this problem, let us all convert the mass of
each element into number of moles using the formula:
moles = mass / molar mass
Where,
molar mass K = 39.10 g / mol
<span>molar mass Cl = 35.45 g / mol</span>
molar mass O = 16 g / mol
<span>and mass O = 13 g – 4.15 g
– 3.76 g = 5.09 g</span>
moles K = 4.15
g / (39.10 g / mol) = 0.106 mol
<span>moles Cl = 3.76 g / (35.45 g / mol) = 0.106 mol</span>
moles O = 5.09 g / (16 g /
mol) = 0.318 mol
The ratio becomes:
0.106 K: 0.106 Cl: 0.318 O
We divide all numbers with
the smallest number, in this case 0.106. This becomes:
K: Cl: 3O
Therefore the empirical formula
is:
