Since the configuration contains the number 2s and 2p, you can assume that it is in period 2 of the periodic table. By noble gas shorthand, you start with helium, which is atomic number 2. 2s²2p^4 has 2+4 = 6 valence
Add 2+6 = 8, which is Oxygen.
Answer:
You should not use an open flame to heat the solvent and the solvent should be heat in a stoppered flask to vapour away from the open flame
Explanation:
Answer:
The groupings of elements in the periodic table reveal various trends, present in groups such as the alkali metals and noble gases, or the lanthanides and actinides. The periodic table can be used to find information on elements or predict the properties of as-of-yet undiscovered elements.
Explanation:
Answer:
Explanation:
<u>1) Data:</u>
a) mass of solute = ?
b) volume of solution = 1.25 liter
c) M = 2.92 mol/liter
d) solute NaOH
<u>2) Formulae:</u>
<u />
a) Molarity, M = number of moles of solute / volume of solution in liters
b) mass in grams = molar mass × number of moles
<u>3) Solution:</u>
a) <u>Calculate number of moles of solute</u>:
- M = number of moles of solute / volume of solution in liters
⇒ number of moles of solute = M × volume of solution in liters
⇒ number of moles of solute = 2.92 mol/liter × 1.25 liter = 3.65 mol
b) <u>Molar mass of NaOH = 39.997 g/mol </u>(you can take this number from internet or calculate it using the atomic masses of Na, O, and H).
c) <u>Calculate the mass of solute:</u>
- mass in grams = molar mass × number of moles = 39.997 g/mol × 3.65 mol = 145.98905 g = 146. g
The answer must be reported with 3 significant figures, so it is 146. g.