<u>Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. The earliest roots of science can be traced to Ancient Egypt and Mesopotamia in around 3000 to 1200 BCE.</u>
Answer is: pH of solution is 3,02.
c(benzoic acid) = 0,03 mol/dm³.
c(sodium benzoate) = 0,02 mol/dm³.
pKa(benzoik acid) = 3,19.
pH = ?
Henderson–Hasselbalch equation for buffers: pH = pKa + log(cs/ck)
pH = 3,19 + log(0,02/0,03)
pH = 3,19 - 0,176
pH = 3,02.
cs - concentration of acid.
Answer:
This question is incomplete, however, the unknown compound can be inferred to be "Lithium Bromide"
Explanation:
The unknown compound firstly is said to be an ionic compound. An ionic/electrovalent compound is a compound in which it's constituent ions transfer/receive electron(s). They are mostly made of group 1 and group 7 elements. Examples include NaCl, NaF, LiF and KCl.
Also, the ion (metallic ion) that produces a red flame test colour in a flame test is the <u>Lithium ion (Li⁺).</u> Also, when dissolved in water or hexane, the only halogen that produces a red/orange colour is bromine. Hence, the unknown ionic compound can be inferred to be Lithium Bromide.
30 electrons = atomic number
Look at your periodic table. You will see zinc has a atomic number (the top number) of 30.
When you add 30 and 35 you get 65. The is the atoms ATOMIC MASS. So looking at zinc on the periodic table, look at its bottom number, which is its atomic mass. It will be 65.
This means the name of the element is ZINC.
Hope this helped!
