3.16 X 10^-11 M is the [OH-] concentration when H3O+ = 1.40 *10^-4 M.
Explanation:
data given:
H30+= 1.40 X 10^-4 M\
Henderson Hasslebalch equation to calculate pH=
pH = -log10(H30+)
putting the values in the equation:
pH = -log 10(1.40 X 10^-4 M)
pH = 3.85
pH + pOH =14
pOH = 14 - 3.85
pOH = 10.15
The OH- concentration from the pOH by the equation:
pOH = -log10[OH-]
10.5= -log10[OH-]
[OH-] = 10^-10.5
[OH-] = 3.16 X 10^-11 is the concentration of OH ions when hydronium ion concentration is 1.40 *10^-4 M.
Answer:
Cu
Explanation:
Groups 3 - 12 (or groups IIA - IIB) of the periodic table contain transition elements. Transaction elements start from period four (4) of the periodic table. The phrase alludes to the fact that the d sublevel is filling at a lower main energy level than the s sublevel that came before it.
The transition elements' arrangement is inverted from the fill order, with the 4 s filled prior to the actual 3 d begins. The transition elements are commonly referred to as transition metals since they are all metals. They are less reactive than the metals in Groups 1 and 2 and have normal metallic characteristics.
From the options given Cu is the only transition metal in the fourth period on the periodic table.
Answer:
The molecular formula = 
Explanation:
Given that:
Mass of compound, m = 0.145 g
Temperature = 200 °C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T = (200 + 273.15) K = 473.15 K
V = 97.2 mL = 0.0972 L
Pressure = 0.74 atm
Considering,
Using ideal gas equation as:
where,
P is the pressure
V is the volume
m is the mass of the gas
M is the molar mass of the gas
T is the temperature
R is Gas constant having value = 0.0821 L.atm/K.mol
Applying the values in the above equation as:-
The empirical formula is =
Molecular formulas is the actual number of atoms of each element in the compound while empirical formulas is the simplest or reduced ratio of the elements in the compound.
Thus,
Molecular mass = n × Empirical mass
Where, n is any positive number from 1, 2, 3...
Mass from the Empirical formula = 12 + 1 = 13 g/mol
Molar mass = 78.31 g/mol
So,
Molecular mass = n × Empirical mass
78.31 = n × 13
⇒ n ≅ 6
The molecular formula = 
Answer:
Cobalt chloride
Explanation:
It is a molecule formed of one Cobalt atom, and two Chlorine atoms.
Answer:
526g is the mass of this sample
Explanation:
To solve this question we must, as first, find the <em>molar mass </em>of Al₂(Cr₂O₇)₃ using the periodic table. The molar mass is defined as the mass of this compound per mole. With this value we can find the mass in 0.750 moles as follows:
<em>Molar mass Al₂(Cr₂O₇)₃</em>
2Al = 2*26.98g/mol = 53.96g/mol
6 Cr = 6*51.9961g/mol = 311.9766g/mol
21 O = 21*15.999g/mol = 335.979g/mol
53.96g/mol + 311.9766g/mol + 335.979g/mol
= 701.9156g/mol
The mass of 0.750 moles is:
0.750 moles * (701.9156g / mol) =
<h3>526g is the mass of this sample</h3>