Answer:
• pH = 3.0
• pH = 2.70
• pH = 3.61
• pH = 8.28
• pH = 1.40
Explanation:
El pH es una medida en química usada para determinar el grado de acidez o basicidad en una solución.
Se define como:
pH = -log₁₀ [H⁺]
<em>El - logaritmo de la concentración molar de H⁺</em>
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Para las concentraciones de H⁺ dadas:
• [H+] = 0.001 M
pH = -log (0.001M) = 3
pH = 3.0
• [H+] = 0.002 M
pH = -log (0.002M)
pH = 2.70
• [H+] = 2.45X10-4 M
pH = -log (2.45X10-4 M )
pH = 3.61
• [H+] = 5.2X10-9 M
pH = -log (5.2X10-9 M)
pH = 8.28
• [H+] = 0.04 M
pH = -log (0.04M)
pH = 1.40
Answer:
V₂ =31.8 mL
Explanation:
Given data:
Initial volume of gas = 45 mL
Initial temperature = 135°C (135+273 =408 K)
Final temperature = 15°C (15+273 =288 K)
Final volume of gas = ?
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 45 mL × 288 K / 408 k
V₂ = 12960 mL.K / 408 K
V₂ =31.8 mL
Answer : The correct answer for mole ratio of H₂O : H₃PO₄ = 6: 4 .
Mole ratio :
It is defined as mole of one substance to another substance in a balanced reaction . In the balanced reaction , the coefficient written before the substances are taken as moles of that substance.
The given balanced reaction between P₄H₁₀ and H₂O is :
P₄O₁₀ + 6 H₂O → 4 H₃PO₄
Mole of H₂O = 6
Mole of H₃PO₄ = 4
Hence mole ratio of Water : H₃PO₄ = 6 : 4
Answer:
Only 3 is correct.
Explanation:
The crystal of a metal or an ionic compound is called a cell, and there are 7 types of unit cells: cubic, tetragonal, orthorhombic, monoclinic, hexagonal, rhombohedral, and triclinic.
In a face-centered cubic cell (FCC) all angles are 90º and all lengths are equal. Each cubic cell has 8 atoms in each corner of the cube, and that atom is shared with 8 neighboring cells. So for a metal crystal, the atom is located at each of the eight lattice points, where it is shared equally between eight unit cells.
Answer:
Ethynylcyclopropane is the stable isomer for given alkyne.
Explanation:
In order to solve this problem we will first calculate the number of Hydrogen atoms. The general formula for alkynes is as,
CₙH₂ₙ₋₂
Putting value on n = 5,
C₅H₂.₅₋₂
C₅H₈
Also, the statement states that the compound contains one ring therefore, we will subtract 2 hydrogen atoms from the above formula i.e.
C₅H₈ ------------(-2 H) ----------> C₅H₆
Hence, the molecular formula for given compound is C₅H₆
Below, 4 different isomers with molecular formula C₅H₆ are attached.
The first compound i.e. ethynylcyclopropane is stable. As we know that alkynes are sp hybridized. The angle between C-C-H in alkynes is 180°. Hence, in this structure it can be seen that the alkyne part is linear and also the cyclopropane part is a well known moiety.
Compounds 3-ethylcycloprop-1-yne, <u>cyclopentyne </u>and 3-methylcyclobut-1-yne are highly unstable. The main reason for the instability is the presence of triple bond in three, five and four membered ring. As the alkynes are linear but the C-C-H bond in these compound is less than 180° which will make them highly unstable.