It is -2 because the charge will be at zero and electrons lower the charge
Answer:
kb = 2,0x10⁻⁵
Explanation:
The ka for HCN is:
HCN ⇄ H⁺ + CN⁻; ka = 4,9x10⁻¹⁰ <em>(1)</em>
The inverse reaction has an equilibrium constant of:
H⁺ + CN⁻ ⇄ HCN k = 1/4,9x10⁻¹⁰ = 2,0x10⁹ <em>(2)</em>
As the equilibrium of the water is:
H₂O ⇄ H⁺ + OH⁻; kw = 1x10⁻¹⁴ <em>(3)</em>
The sum of (2) + (3) gives:
H₂O + CN⁻ ⇄ HCN + OH⁻; kb = kw×k = 1x10⁻¹⁴×2,0x10⁹ =
2,0x10⁻⁶; <em>kb = 2,0x10⁻⁵</em>
<em />
<em>-In fact, the general formula to convert from ka to kb is:</em>
<em>kb = kw / ka-</em>
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I hope it helps!
<span>C. The number of electrons the element needs to lose or gain to have a full valence shell</span>
Answer:
3.74%
Explanation:
We express a solution's volume by volume percent concentration, % v/v,
Take the ratio of the isopropyl alcohol (IPA) volume to the total volume of the solution, which is 1800 mL of water+ 70 mL of IPA,
and multiply by 100 to get the percentage: 70/(1800+70) *100 = 0.0374*100 = 3.74%
Answer:
The ball will fly tangential to the original circle
Explanation:
The image here is missing, however we can still answer to the question.
In fact, the circular motion of the ball when it is tied to the rope is a combination of two separate effects:
1- The centripetal force, in the form of the tension in the rop, that pulls the ball at any time towards the centre of the circular path
2- The inertia of the ball, which tends to continue its motion in a straight direction, tangential to the circle and perpendicular to the direction of the centripetal force
When child let the string go, there is no more tension in the string acting on the ball, and therefore, there is no longer a centripetal force.
As a result, number 1) disappears, and therefore there is only the inertia of the ball that will determine its motion: and therefore, the ball will continue its motion straight in a direction tangential to the original circle.
