Answer: It is important to wet the filter paper in the Buchner funnel first with cold re crystallization solvent before the re crystallization mixture being filtered to minimize gaps around the edges of the filter paper which can prevent mechanical impurities from passing through. This gives better filtration where most impurities can be filtered. Furthermore, it provides good vacuum.
Nitrogen atom has a valence electrons of 5 electrons. A full octet or full valence electrons shell is composed of 8 electrons. Hence, an additional of 4 electrons are needed for it to become full. this is achieved by covalent bonding where electrons are shared or ionic bonding where electrons are transferred.
The answer is Rubidium (Rb)
Answer:
1.54grams
Explanation:
Molarity of a solution = n/V
Where;
n = number of moles (mol)
V = volume (L)
Based on the information given in this question;
Volume of NaOH solution = 5.0 × 10ml
= 50ml = 50/1000 = 0.050 L
Molarity = 0. 77 M
Using; Molarity = n/V
0.77 = n/0.05
n = 0.77 × 0.05
n = 0.0385mol
To find the mass (grams) of NaOH in the solution, we use the following formula:
mole (n) = mass/molar mass
Molar mass of NaOH = 23 + 1 + 16 = 40g/mol
0.0385 = mass/40
mass = 0.0385 × 40
mass = 1.54grams.
