Answer:
Kb = 2.23 x 10⁻⁵
Explanation:
Benz-CO-NH₂ + H₂O => Benz-CO-NH₃⁺OH⁻ ⇄ Benz-CO-NH₃⁺ + OH⁻
given pOH = 2.91 => [OH⁻] = 10E-2.91 = 1.23 x 10⁻³M
Benz-CO-NH₃⁺OH⁻ ⇄ Benz-CO-NH₃⁺ + OH⁻
At Equilibrium 0.68M 1.23 x 10⁻³M 1.23 x 10⁻³M
Kb = [Benz-CO-NH₃⁺][OH⁻]/[ Benz-CO-NH₃⁺OH⁻]
= (1.23 x 10⁻³)² M²/ 0.068M = 2.23 x 10⁻⁵
Answer:
Mass= 314.96 grams
Explanation:
The density of the substance is defined as mass per unit volume of it.
The formula is :

<u><em>Unit conversion:</em></u>
1 liter = 1000 ml

So
....(1)


Replace The dm3 by cm3 in (1)

<u>
</u>
<u>Volume = 254 mL = 254 cm3</u>
<em><u>Calculation of mass</u></em>



Mass= 314.96 grams(or 315 grams)
Note: Always makes same units before solving the question. You can not determine the mass if Volume is in mL and Density is in g/cm3. Change mL into cm3 first
<span>Chemical bonds hold combinations of atoms together in molecules. These chemical bonds, called covalent bonds or molecular bonds, are formed when two atoms share electron pairs. Some other types of chemical bonds are ionic bonds and metallic bonds.</span>
Answer:
B
Explanation:
Firstly, we will need to calculate the number of moles. To do this, we make use of the ideal gas equation
PV = nRT
n = PV/RT
The parameters have the following values according to the question:
P = 780mmHg, we convert this to pascal.
760mHG = 101325pa
780mmHg = xpa
x = (780 * 101325)/760 = 103,991 Pa
V= 400ml = 0.4L
T = 135C = 135 + 273.15 = 408.15K
n = ?
R = 8314.463LPa/K.mol
Substituting these values into the equation yields the following:
n = (103991 * 0.4)/(8314.463 * 408.15)
= 0.012 moles
Now we know 1 mole contains 6.02 * 10^23 molecules, hence, 0.012moles will contain = 0.012 * 6.02 * 10^23 = 7.38 * 10^21 molecules
Iron(II) oxide react with nitric acid to produce iron(III) nitrate, nitrogen dioxide and water. Chemical reaction<span>. Balancing </span>chemical<span> equations.</span>