Answer:
A
Explanation:
Ball bounces because of the difference in the air pressure on the outside of the ball, and opposite the point of impact, and the pressure inside of the ball. This means that the inside of the ball now has less space to contain the air molecules contained inside the ball, increasing the pressure inside the ball.
So there are three formulas that you must be aware of hen attempting these questions (by technicality, only two because the third is a transposition of the second).
These formulas are :
mole x L = # of atoms (where L = Avogadro's Constant)
mass / Mr = mole (where Mr = Molar Mass)
Mole x Mr = mass
So no we can easily ace these questions
1) a. 98.3 g of Hg
mass of Hg = 98.3g
Mr " " = 201 g / mol
mole =
= 0.489 mol
∴ # of atoms = 0.489 mol * (6.03 * 10²³)
= 2.95 * 10²³ atoms
c. 10.7g of Li
mass of Li = 10.7 g
Mr " " = 7 g / mol
thus mole =
= 1.529 mol
# of atoms = 1.529 mol * (6.03 * 10²³)
= 9.22 * 10²³
2) a. 6.84 g of C₁₂H₂₂O₁₁
mass of sucrose = 6.84 g
Mr " " = ∑ (Mr of each element * amount of each element's atom)
= ∑ [(12 * 12)+(1 * 12)+(16 * 11)] g / mol
= 342 g / mol
∴ mole of sucrose =
= 0.02 mol
c) 68.0g of NH<span>₃</span>
<span> mass of NH₃ = 68.0 g</span>
<span> Mr " " = [(14 * 1) + ( 1 * 3)] g / mol</span>
<span> ∴ mole of NH₃ = </span>
= 4 mol
3) a. 3.52 mol of Si
mole of Si = 3.52 mol
Mr " " = 28 g / mol
Mass = 3.52 mol * 28 g / mol
= 98.56 g
c. 0.550 mol of F₂
mol of F₂ = 0.55 mol
Mr " " = (19 * 2 ) g / mol
Mass = 0.55 mol * 38 g / mol
= 20.9 g
Hope I as clear in my answers and that they helped
the pH during the titration of 40.00 mL of 0.1000 M HCl after adding 50 mL of 0.1000 M NaOH is pH = 13.39
NaOH + HCl → NaCl + H2O
40.00 ml 0.5M NaOH solution
mol NaOH = 40 ml / 1000 ml / L * 0.5 mol / L = 0.02 mol NaOH
25 mL 0.1 M HCl
mol HCl = 25 mL / 1000 mL / L * 0.1 mol / L = 0, 0025 mol
This reacts with 0.0025 mol NaOH
[NaOH] = 0.269 M
[OH-] = 0.269 M
pOH = - log 0.269
pOH = 13.43
You titrate with 30 mL 0.100 M HCl
Mol HCl = 30 mL / 1000 mL/L * 0.100 mol /L = 0.003 mol HCl
This will react with 0.003 mol NaOH
Mol unreacted NaOH = 0.02 mol - 0.003 mol = 0.017 mol NaOH in 40mL + 30 mL = 70 mL solution
Molarity of NaOH solution = 0.017 mol / 70 mL * 1000 mL/L = 0.243 M
[OH-] = 0.243 M
pOH = - log 0.243
pOH = 0.61
pH = 13.39
40 mL
Titration is defined as "the process of determining the amount of substance A by adding a measured amount of substance B, which is a titrator that reacts until an accurate chemical equivalence point is reached."
Learn more about titration here: brainly.com/question/186765
#SPJ4
Which of the following processes moves rock materials across the surface of the earth?
C. Erosion
Good luck! :)