Answer:
C
Explanation:
The early ideas of the atom states that the indivisible object is hollow or is a solid object with nothing inside. The later discoveries or works of the scientists states that inside the atoms are the subatomic particles which are the electrons, protons, and neutrons.
According to the reaction equation:
CH3COO- + H+ → CH3COOH
initial 0.25 0.15
change - 0.025 + 0.025
Equ (0.25-0.025) (0.15 + 0.025)
first, we have to get moles acetate and moles acetic acid:
moles of acetate = 0.25 - 0.025 = 0.225 moles
∴ [CH3COO-] = 0.225 mol / 1 L = 0.225 M
moles of acetic acid = 0.15 + 0.025 = 0.175 moles
∴ [ CH3COOH] = 0.175 mol / 1L = 0.175 M
Pka = -㏒ Ka
= -㏒ 1.8 x 10^-5
= 4.74
from H-H equation we can get the PH value:
PH = Pka + ㏒ [acetate / acetic acid]
PH = 4.74 + ㏒[0.225/0.175]
∴ PH = 4.8
Answer:
0.43 mol.
Explanation:
- Knowing that the no. of moles can be calculated using the relation:
<em>no. of moles (n) = mass/molar mass</em>
mass of MgCl₂ = 41.0 g & molar mass of MgCl₂ = 95.211 g/mol.
<em>∴ n = mass/molar mass</em> = (41.0 g)/(95.211 g/mol) = <em>0.43 mol.</em>
Answer:
The interaction reaction of calcium oxide and water leads to the formation of calcium hydroxide, this reaction is exothermic, which indicates that energy is released.
CaO(s) + H2O ⇒ Ca(OH)2
Explanation:
Calcium oxide reacts violently with water, causing it to reach 90 C. It then forms calcium hydroxide, also called slaked lime. It is heated because it releases energy in the form of heat, because the new substance formed (slaked lime) has less internal energy than the original and this is released in the form of heat. As a general rule, acid and base solutions are exothermic.
Answer:
For a constant wavelength, Increase in frequency will increase in velocity of the wave. Example: For a constant wavelength, If frequency is doubled. The velocity of the wave will also double.
Explanation:
