Answer:
2. 14
Explanation:
To form Br₂ bond, a total of 14 electrons are needed.
Bromine is an element in the 7th group on the periodic table. It has 7 valence electrons.
- In forming the bromine gas, the two atoms of bromine shares 7 electrons each.
- These electrons are from their outermost shell.
- The outermost shell is the valence shell.
- So, two atoms donating 7 electrons gives 14 electrons.
Answer:
hco I believe
Explanation:
Pretty sure about this, when do you need to put it in?
Triprotic acid is a class of Arrhenius acids that are capable of donating three protons per molecule when dissociating in aqueous solutions. So the chemical reaction as described in the question, at the third equivalence point, can be show as: H3R + 3NaOH ⇒ Na3R + 3H2O, where R is the counter ion of the triprotic acid. Therefore, the ratio between the reacted acid and base at the third equivalence point is 1:3.
The moles of NaOH is 0.106M*0.0352L = 0.003731 mole. So the moles of H3R is 0.003731mole/3=0.001244mole.
The molar mass of the acid can be calculated: 0.307g/0.001244mole=247 g/mol.
<span>To find the molar mass, look at a periodic table for each element.
Ibuprofen, C13 H18 and O2. Carbon has a molar mass of 12.01 g, Hydrogen has 1.008 g per mole, and Oxygen is 16.00 g per mole.
C: 13 * 12.01
H: 18 * 1.008
O: 2 * 16.00
Calculate that, add them all together, and that is the molar mass of C13H18O2.
Molar mass: 206.274
Next, you have 200mg in each tablet, with a ratio of C13H18O2 (molar mass) in GRAMS per Mole
So, you need to convert miligrams into grams, which is 200 divided by 1000.
0.2 g / Unknown mole = 206.274 g / 1 Mole
This is a cross multiplying ratio where you're going to solve for the unknown moles of grams per tablet compared to the moles per ibuprofen.
So, it's set up as:
0.2 g * 1 mole = 206.274 * x
0.2 = 206.274x
divide each side by 206.274 to get X alone
X = 0.00097
or 9.7 * 10^-4 moles
The last problem should be easy to figure out now that you have the numbers. 1 dose is 2 tablets, which is the moles we just calculated above, times four for the dosage.
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