Answer:
The molar mass of the unknown acid is 386.8 g/mol
Explanation:
Step 1: Data given
Mass of the weak acid = 1.168 grams
volume of NaOH = 28.75 mL = 0.02875 L
Molarity of NaOH = 0.105 M
Since we only know 1 equivalence point, we suppose the acid is monoprotic
Step 2: Calculate moles NaOH
Moles NaOH = molarity NaOH * volume NaOH
Moles NaOH = 0.105 M * 0.02875 L
Moles NaOH = 0.00302 moles
We need 0.00302 moles of weak acid to neutralize the NaOH
Step 3: Calculate molar mass of weak acid
Molar mass = mass / moles
Molar mass = 1.168 grams / 0.00302 moles
Molar mass = 386.8 g/mol
The molar mass of the unknown acid is 386.8 g/mol
Answer:
5 , I think. sorry if its wrong
Answer:
D
Explanation:
Oxygen is the 8th element in the periodic table. This means that oxygen has 8 protons and 8 electrons. In order to get the number of neutrons you take the atomic weight in this case 15.9999~16 and you subtract it by the number of protons (16-8).
<span>It is used for the separation of fluids, gas or liquid, based on density.
Hope this helps!</span>
The alkali metals are so reactive that they are never found in nature in elemental form. Although some of their ores are abundant, isolating them from their ores is somewhat difficult. For these reasons, the group 1 elements were unknown until the early 19th century, when Sir Humphry Davy first prepared sodium (Na) and potassium (K) by passing an electric current through molten alkalis. (The ashes produced by the combustion of wood are largely composed of potassium and sodium carbonate.) Lithium (Li) was discovered 10 years later when the Swedish chemist Johan Arfwedson was studying the composition of a new Brazilian mineral. Cesium (Cs) and rubidium (Rb) were not discovered until the 1860s, when Robert Bunsen conducted a systematic search for new elements. Known to chemistry students as the inventor of the Bunsen burner, Bunsen’s spectroscopic studies of ores showed sky blue and deep red emission lines that he attributed to two new elements, Cs and Rb, respectively. Francium (Fr) is found in only trace amounts in nature, so our knowledge of its chemistry is limited. All the isotopes of Fr have very short half-lives, in contrast to the other elements in group 1.
