Answer:
The compound you will use is the Dibasic phosphate
Explanation:
Simple phosphate buffer is used ubiquitously in biological experiments, as it can be adapted to a variety of pH levels, including isotonic. This wide range is due to phosphoric acid having 3 dissociation constants, (known in chemistry as a triprotic acid) allowing for formulation of buffers near each of the pH levels of 2.15, 6.86, or 12.32. Phosphate buffer is highly water soluble and has a high buffering capacity,
In this case the most efficient way is to disolve the dibasic compound which in the reaction with the water will form the monobasic phosphate.
To make the buffer you have to prepare the amount of distillate water needed, disolve the dibasic phospate, and then adjust with HCl or NaOH depending on the pH needed.
An alpha particle is identical to a helium atom that has been stripped of its two electrons
I think it might be C or D
Answer: The results of Rutherford's gold foil experiment gave him the evidence to arrive at two conclusions: (1) an atom was much more than just empty space and scattered electrons and (2) an atom consists of a positive charge at the center where most of its mass is placed.
Explanation:
Ernest Rutherford performed an experiment in which he passed alpha particles through a thin gold foil sheet. Through this sheet some of the particles passed on to the other side but some of them were reflected back.
This experiment was done by Rutherford to prove than an atom contains a tiny and heavy nucleus. He concluded that an atom has more than empty space and electrons were present in scattered form.
Also, he concluded that an atom consists of a positive charge at the center where most of its mass is placed.
Thus, we can conclude that the results of Rutherford's gold foil experiment gave him the evidence to arrive at two conclusions: (1) an atom was much more than just empty space and scattered electrons and (2) an atom consists of a positive charge at the center where most of its mass is placed.
KOH is a strong base and HBr is a strong acid and completely dissociates.
The balanced equation for the reaction is;
KOH + HBr ---> KBr + H₂O
Stoichiometry of acid to base is 1:1
The number of KOH moles reacted - 0.50 M / 1000 mL/L x 48.0 mL = 0.024 mol
number of HBr moles reacted - 0.25 M/ 1000 mL/L x 96.0 mL = 0.024 mol
the number of H⁺ ions are equal to number of OH⁻ ions.
Then the solution is neutral.
pH of neutral solutions at 25 °C is 7.
Therefore pH is 7