Answer:
3.41 g
Explanation:
<em>A chemist adds 260.0 mL of a 0.0832 M potassium permanganate solution to a reaction flask. Calculate the mass in grams of potassium permanganate the chemist has added to the flask.</em>
Step 1: Given data
- Volume of the solution (V): 260.0 mL (0.2600 L)
- Molar concentration of the solution (C): 0.0832 M (0.0832 mol/L)
Step 2: Calculate the moles (n) of potassium permanganate added
We will use the following expression.
n = C × V
n = 0.0832 mol/L × 0.2600 L = 0.0216 mol
Step 3: Calculate the mass corresponding to 0.0216 moles of potassium permanganate
The molar mass of potassium permanganate is 158.03 g/mol.
0.0216 mol × 158.03 g/mol = 3.41 g
The reaction that should be followed is
Na2SO4 + C<span>a(NO3)2 --> CaSO4 + 2NaNO3</span>
first calculate the limiting reactant
mol Na2SO4 = 0.075 L (<span>1.54×10−2 mol / L) = 1.155x10-3 mol
mol Ca(NO3)2 = 0.075 L (</span><span>1.22×10−2 mol / L) = 9.15x10-4 mol
so the limiting reactant is the Ca(NO3)2
so all of the Ca2+ will be precipitated, percentage unprecipitated = 0.00 % </span>
Answer: sp2 hybridized orbital
Explanation:
The lone pair in pyridine is contained in an sp2 hybridized orbital pointing outwards from the ring. As a result, the lone pair does not contribute to the aromatic ring but still influences the properties of pyridine such as electrophilic attack. The image attached depicts the bonding in pyridine.
This is actually really is. Notice how the protons + the neutrons equal the top number next to the element and the bottom one is the amount of protons.
So for Rn, it already gives you the protons and the atomic number (the top number), you just subtract them ---> 209-86= 123 neutrons.
I don't have a periodic table to look at, but for the next one just add the protons and the neutrons to get the atomic number (the atomic number will be under the element symbol) and look for it on the periodic table to find the element and so on.
I hope this helps ♥