The ML of 0.85 m NaOH required to titrate 25 ml of 0.72m hbr to the equivalence point is calculated as follows
calculate the moles of HBr used
moles = molarity x volume
25 x0.072/1000= 0.0018 moles
write the equation for reaction
NaOH + HBr = NaBr + H2O
from reacting equation the mole ratio between NaOH to HBr is 1:1 therefore the moles of NaOH = 0.0018 moles
volume = moles/molarity
0.0018/0.085 = 0.021 L in Ml = 0.021 x1000=21.18 Ml ofNaOH
First let us calculate for the molar mass of ibuprofen:
Molar mass = 13 * 12 g/mol + 18 * 1 g/mol + 2 * 16 g/mol
Molar mass = 206 g/mol = 206 mg / mmol
Calculating for the number of moles:
moles = 200 mg / (206 mg / mmol)
moles = 0.971 mmol = 9.71 x 10^-4 moles
Using the Avogadros number, we calculate the number of
molecules of ibuprofen:
Molecules = 9.71 x 10^-4 moles * (6.022 x 10^23 molecules
/ moles)
<span>Molecules = 5.85 x 10^20 molecules</span>
The correct answer is A. Charging by friction
Explanation
When someone rubs a comb with their hair when they are combing it and the hair sticks to the comb occurs a phenomenon called electrization, in which a neutral body becomes charged or loses an electrical charge (electrons). One way that electrization occurs is through the rubbing of two neutral bodies which causes one to be positively charged and the other negatively causing them to attract each other by magnetism. Therefore, the correct answer is A. Charging by friction
Answer:
Kp = 8.76×10⁻³
Explanation:
We determine the carbamate decomposition in equilibrium:
NH₄CO₂NH₂ (s) ⇄ 2NH₃(g) + CO₂(g)
Let's build the expression for Kp
Kp = (Partial pressure NH₃)² . Partial pressure CO₂
We do not consider, the carbamate because it is solid and we only need the partial pressure from gases
Kp = (0.370atm)² . 0.0640 atm
Kp = 8.76×10⁻³
Remember Kp does not carry units
What poison ivy looks like:
Each leaf has 3 little leaflets. It tends to grow off-white berries on the leaves in the early fall, and grows yellow-green flowers in the spring.
Treating poison ivy:
If you have a rash from poison ivy, it is recommended to rinse your skin off with lukewarm water immediately after you notice the rash.
Make sure to wash your clothing since the oil from the plant can stick to your clothing.
Do not scratch at the rash, as scratching will cause an infection.
If blisters appear on your skin, do not mess with them as it can prevent infection.
How to kill poison ivy:
If you find the plant, do not pull or burn it. Even if you pull it, it will still grow out of the ground since you did not eliminate the roots of it. Burning it can release <span>urushiol into the air which can be harmful.
</span>It is recommended to use a specialized weed killing spray. Always look at the ingredients in the spray and look for: Triclopyr, which fights through the surface of the plant, and also <span>glyphosate, that helps kill the roots of the plant.
</span>Once you use a spray, it will take 1-2 weeks for it to die. It will eventually turn yellowish-brownish.
Important:
Poison ivy contains urushiol which can cause allergic reaction.
Burning poison ivy releases urushiol into the air which can also cause allergic reaction and can be harmful.