Answer:
The answer is "
"
Explanation:
Given:
Molarity= number of moles
because it is 1 Liter
therefore,
it takes 20 mL of Tris.
So, take 
Explanation:
Since HF is a weak acid, the use of an ICE table is required to find the pH. The question gives us the concentration of the HF.
HF+H2O⇌H3O++F−HF+H2O⇌H3O++F−
Initial0.3 M-0 M0 MChange- X-+ X+XEquilibrium0.3 - X-X MX M
Writing the information from the ICE Table in Equation form yields
6.6×10−4=x20.3−x6.6×10−4=x20.3−x
Manipulating the equation to get everything on one side yields
0=x2+6.6×10−4x−1.98×10−40=x2+6.6×10−4x−1.98×10−4
Now this information is plugged into the quadratic formula to give
x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)−−−−−−−−−−−−−−−−−−−−−−−−−−−−√2x=−6.6×10−4±(6.6×10−4)2−4(1)(−1.98×10−4)2
The quadratic formula yields that x=0.013745 and x=-0.014405
However we can rule out x=-0.014405 because there cannot be negative concentrations. Therefore to get the pH we plug the concentration of H3O+ into the equation pH=-log(0.013745) and get pH=1.86
The last one. A bond of two or more of the same element.
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.
