From the periodic table:
molar mass of carbon = 12 gm
molar mass of hydrogen = 1 gm
molar mass of oxygen = 16 gm
molar mass of <span>acetylsalicylic acid = 9(12) + 8(1) + 4(16) = 180 gm
Number of moles = mass / molar mass = 0.5 / 180 = 2.778 x 10^-3 moles
To get the number of molecules, we multiply the number of moles by Avogadro's number as follows:
number of molecules = </span>2.778x10^-3x6.02x10^23 =1.672 x 10^21 molecules
Answer:
A
Explanation:
The molecules in both metal and surrounding air will start moving slower because of the sudden decrease in environment tmeperature. The thermal energy around the metal plate decreases, also decreasing the kinetic energy.
Answer:
the triangular model and the cubic model
The second stage of photosynthesis also called Calvin stage produces glucose
Answer:
0.42%
Explanation:
<em>∵ pH = - log[H⁺].</em>
2.72 = - log[H⁺]
∴ [H⁺] = 1.905 x 10⁻³.
<em>∵ [H⁺] = √Ka.C</em>
∴ [H⁺]² = Ka.C
∴ ka = [H⁺]²/C = (1.905 x 10⁻³)²/(0.45) = 8.068 x 10⁻⁶.
<em>∵ Ka = α²C.</em>
Where, α is the degree of dissociation.
<em>∴ α = √(Ka/C) </em>= √(8.065 x 10⁻⁶/0.45) = <em>4.234 x 10⁻³.</em>
<em>∴ percentage ionization of the acid = α x 100</em> = (4.233 x 10⁻³)(100) = <em>0.4233% ≅ 0.42%.</em>
