Answer:
The volume of a ball that is 24 cm across is :
d). v = four-thirds pi 12 cubed
Explanation :
Ball is a sphere and volume of sphere is given by :
r = radius of ball
r = 12 cm
Volume is :
Answer:
+1
Explanation:
A Potassium atom is represented with the sign "K" in chemistry and have atomic number 19.
The charge of electrons causes a matter to experience a force and it can be positive or negative.
In Potassium atom, the electric charge is +1 to enter a stable electron configuration as there is only one valence electron in the outermost shell of potassium atom. As potassium atom will lose electron it will become positively charged.
Hence, the correct answer is "+1".
Answer:
let's summarize the caution as we are given with human projection. We have to tell them stances where staggered confirmation is not the lowest in energy. Okay, so let's see that. Are there any instances that which conforms tiger is not the lowest energy. Okay, so the lowest energy is what then happened? The lowest in energy already happens on living. Honestly, when, when it happens the lowest in energy only happens when the bulky groups are at 1 80 degree with each other. When it happens when bulky, bulky, bulky groups are at 1 80 degree. Okay, When they are, for example, when the bulky groups are in this way At 180°, then it is Louis Why? Because repulsion are very less repulsion very less. Got it. So we have to tell when it is not the lowest so far not the lowest instance. These bulky groups should be together. So if they either make of angle of 60° or 300° together, suppose this is a bulky group one and this is a bulky group two and okay, so if it makes a 60 degree or 300 degree then this um have the highest energy Or has the energy is not lowest in it. Why? It is not lowest in it Because at 300° or 60°. Why? Because the pulsations are very high repulsion. Are you ready? Hi. So by looking at the humans projection we can conclude that when the if the bulky group parrot 1, 80 degree be considered as the lowest energy. And if they are at 300 or 60 degree or close to each other, republicans are higher and they are not in lowest energy.
Answer:
Explanation:
a) Balanced equation
The balanced chemical equation for the titration is
b) pH at start
For simplicity, let's use B as the symbol for NH₃.
The equation for the equilibrium is
(i) Calculate [OH]⁻
We can use an ICE table to do the calculation.
B + H₂O ⇌ BH⁺ + OH⁻
I/mol·L⁻¹: 0.150 0 0
C/mol·L⁻¹: -x +x +x
E/mol·L⁻¹: 0.150 - x x x
![K_{\text{b}} = \dfrac{\text{[BH}^{+}]\text{[OH}^{-}]}{\text{[B]}} = 1.8 \times 10^{-5}\\\\\dfrac{x^{2}}{0.150 - x} = 1.8 \times 10^{-5}](https://tex.z-dn.net/?f=K_%7B%5Ctext%7Bb%7D%7D%20%3D%20%5Cdfrac%7B%5Ctext%7B%5BBH%7D%5E%7B%2B%7D%5D%5Ctext%7B%5BOH%7D%5E%7B-%7D%5D%7D%7B%5Ctext%7B%5BB%5D%7D%7D%20%3D%201.8%20%5Ctimes%2010%5E%7B-5%7D%5C%5C%5C%5C%5Cdfrac%7Bx%5E%7B2%7D%7D%7B0.150%20-%20x%7D%20%3D%201.8%20%5Ctimes%2010%5E%7B-5%7D)
Check for negligibility:
(ii) Solve for x
![\dfrac{x^{2}}{0.150} = 1.8 \times 10^{-5}\\\\x^{2} = 0.150 \times 1.8 \times 10^{-5}\\x^{2} = 2.7 \times 10^{-6}\\x = \sqrt{2.7 \times 10^{-6}}\\x = \text{[OH]}^{-} = 1.64 \times 10^{-3} \text{ mol/L}](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%5E%7B2%7D%7D%7B0.150%7D%20%3D%201.8%20%5Ctimes%2010%5E%7B-5%7D%5C%5C%5C%5Cx%5E%7B2%7D%20%3D%200.150%20%5Ctimes%201.8%20%5Ctimes%2010%5E%7B-5%7D%5C%5Cx%5E%7B2%7D%20%3D%202.7%20%5Ctimes%2010%5E%7B-6%7D%5C%5Cx%20%3D%20%5Csqrt%7B2.7%20%5Ctimes%2010%5E%7B-6%7D%7D%5C%5Cx%20%3D%20%5Ctext%7B%5BOH%5D%7D%5E%7B-%7D%20%3D%201.64%20%5Ctimes%2010%5E%7B-3%7D%20%5Ctext%7B%20mol%2FL%7D)
(iii) Calculate the pH
![\text{pOH} = -\log \text{[OH}^{-}] = -\log(1.64 \times 10^{-3}) = 2.78\\\\\text{pH} = 14.00 - \text{pOH} = 14.00 - 2.78 = \mathbf{11.22}\\\\\text{The pH of the solution at equilibrium is } \large \boxed{\mathbf{11.22}}](https://tex.z-dn.net/?f=%5Ctext%7BpOH%7D%20%3D%20-%5Clog%20%5Ctext%7B%5BOH%7D%5E%7B-%7D%5D%20%3D%20-%5Clog%281.64%20%5Ctimes%2010%5E%7B-3%7D%29%20%3D%202.78%5C%5C%5C%5C%5Ctext%7BpH%7D%20%3D%2014.00%20-%20%5Ctext%7BpOH%7D%20%3D%2014.00%20-%202.78%20%3D%20%5Cmathbf%7B11.22%7D%5C%5C%5C%5C%5Ctext%7BThe%20pH%20of%20the%20solution%20at%20equilibrium%20is%20%7D%20%5Clarge%20%5Cboxed%7B%5Cmathbf%7B11.22%7D%7D)
(c) pH at equivalence point
(i) Calculate the moles of each species
B + HI ⇌ BH⁺ + I⁻
I/mol: 3.00 3.00 0
C/mol: -3.00 -3.00 +3.00
E/mol/: 0 0 3.00
(ii) Calculate the concentration of BH⁺
At the equivalence point we have a solution containing 3.00 mmol of NH₄I
Volume = 20.00 mL + 20.00 mL = 40.00 mL
![\rm [BH^{+}] = \dfrac{\text{3.00 mmol}}{\text{40.00 mL}} = \text{0.0750 mol/L}](https://tex.z-dn.net/?f=%5Crm%20%5BBH%5E%7B%2B%7D%5D%20%3D%20%5Cdfrac%7B%5Ctext%7B3.00%20mmol%7D%7D%7B%5Ctext%7B40.00%20mL%7D%7D%20%3D%20%5Ctext%7B0.0750%20mol%2FL%7D)
(iii) Calculate the concentration of hydronium ion
We can use an ICE table to organize the calculations.
BH⁺+ H₂O ⇌ H₃O⁺ + B
I/mol·L⁻¹: 0.0750 0 0
C/mol·L⁻¹: -x +x +x
E/mol·L⁻¹: 0.0750 - x x x
![\dfrac{x^{2}}{0.0750} = 5.56 \times 10^{-10}\\\\x^{2} = 0.0750 \times 5.56 \times 10^{-10}\\x^{2} = 4.17 \times 10^{-11}\\x = \sqrt{4.17 \times 10^{-11}}\\\rm [H_{3}O^{+}] =x = 6.46 \times 10^{-6}\, mol \cdot L^{-1}](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%5E%7B2%7D%7D%7B0.0750%7D%20%3D%205.56%20%5Ctimes%2010%5E%7B-10%7D%5C%5C%5C%5Cx%5E%7B2%7D%20%3D%200.0750%20%5Ctimes%205.56%20%5Ctimes%2010%5E%7B-10%7D%5C%5Cx%5E%7B2%7D%20%3D%204.17%20%5Ctimes%2010%5E%7B-11%7D%5C%5Cx%20%3D%20%5Csqrt%7B4.17%20%5Ctimes%2010%5E%7B-11%7D%7D%5C%5C%5Crm%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%3Dx%20%3D%206.46%20%5Ctimes%2010%5E%7B-6%7D%5C%2C%20mol%20%5Ccdot%20L%5E%7B-1%7D)
(iv) Calculate the pH
![\text{pH} = -\log{\rm[H_{3}O^{+}]} = -\log{6.46 \times 10^{-6}} = \large \boxed{\mathbf{5.19}}](https://tex.z-dn.net/?f=%5Ctext%7BpH%7D%20%3D%20-%5Clog%7B%5Crm%5BH_%7B3%7DO%5E%7B%2B%7D%5D%7D%20%3D%20-%5Clog%7B6.46%20%5Ctimes%2010%5E%7B-6%7D%7D%20%3D%20%5Clarge%20%5Cboxed%7B%5Cmathbf%7B5.19%7D%7D)
The titration curve below shows the pH at the beginning and at the equivalence point of the titration.
Answer:
Birds are able to sit on electrical power lines because the electrical current essentially ignores the bird's presence and continues to travel through the wire instead of through the bird's body. A bird's body is not a good conductor of electricity.
hope i helped
