Fecl3 has a RFM of 56 + (35.5 * 3) = 162.5
so find out its moles 16.5 ÷ 162 5 = aprox. 0.1M
then there is a 1 : 3 ratio so 0.1 * 3 = 0.3
then times that by the avogado constant which is 6.02×10^23
0.3 × 6.02×10^23 = ans
hope that helps
Answer:
(3) 5.36
Explanation:
Since this is a titration of a weak acid before reaching equivalence point, we will have effectively a buffer solution. Then we can use the Henderson-Hasselbalch equation to answer this question.
The reaction is:
HAc + NaOH ⇒ NaAc + H₂O
V NaOH = 40 mL x 1 L/1000 mL = 0.040 L
mol NaOH reacted with HAc = 0.040 L x 0.05 mol/L = 0.002 mol
mol HAC originally present = 0.050 L x 0.05 mol/L = 0.0025 mol
mol HAc left after reaction = 0.0025 - 0.002 = 0.0005
Now that we have calculated the quantities of the weak acid and its conjugate base in the buffer, we just plug the values into the equation
pH = pKa + log ((Ac⁻)/(HAc))
(Notice we do not have to calculate the molarities of Ac⁻ and HAc because the volumes cancel in the quotient)
pH = -log (1.75 x 10⁻⁵) + log (0.002/0.0005) = 5.36
THe answer is 5.36
Answer:
A. The model could not explain how alpha particles could be deflected at large angles.
Explanation:
The plum pudding model of the atom was proposed by J. J Thomson. He suggested that that an atom is made up of dense particles of electrons surrounded by positive charges.
From the Gold foil experiment carried out by Ernest Rutherford, he noticed that the bulk of the alpha particles targeted at the foil passed through and a little fraction was heavily deflected back.
Rutherford then presented his nuclear model from here. He suggested a massive, dense and tiny nucleus where the protons and neutrons are located. The space outside the mass is dominated by orbiting electrons.
The answer is; C
The radioisotopes in the interior of the earth are not in pure form and have many embedded impurities and are interspersed. Therefore when a neutron is released by a decaying atom, its chances of hitting another radioisotope atom (to continue the chain reaction) are lower than in a manmade nuclear reactor. This way, the radioactive chain reaction in the earth’s interior is not well sustained.
Answer: Neutral Value
Explanation: pH of the blood is maintained at 7.0 to 7.5that is neutral value.
This is because if the pH of the is lower than the maintained value then it will become acidic .
Acidic pH can cause the medical urgency known as acidosis leading to vomiting, diarrhea etc.
If the pH becomes higher, then the blood will become basic in nature and it can also leas to the death of the person.
That is why the pH of the blood is maintianed at neutral value of 7.0 to 7.5
