Answer:

Explanation:
We can use the Noyes-Whitney equation to calculate the rate of dissolution.

Data:
D = 1.75 × 10⁻⁷ cm²s⁻¹
A = 2.5 × 10³ cm²
Cₛ = 0.35 mg/mL
C = 2.1 × 10⁻⁴ mg/mL
d = 1.25 µm
Calculations:
Cₛ - C = (0.35 - 2.1 × 10⁻⁴) mg·cm⁻³ = 0.350 mg·cm⁻³
d = 1.25 µm = 1.25 × 10⁻⁶ m = 1.25 × 10⁻⁴ cm

Answer:
The relative densities of an object and the liquid it is placed in determine whether that object will sink or float. An object that has a higher density than the liquid it's in will sink. An object that has a lower density than the liquid it's in will float.
Explanation:
Hope it helps!
A. The longest carbon chain is eight, and it has two methyl groups attached to carbon three, and a special group attached to carbon five. Its two names could be:
3-dimethyl-5-(1-methylethyl)octane
3-dimethyl-5-isopropyloctane
Both of these are correct. This is an alkane, because it has all single bonds.
B. This has a triple bond contained between carbons 2 and 3, and has a methyl group off carbon 4. The longest chain is 5. It’s name is:
4-methyl-2-pentyne
This is an alkene, because of the double bond.
C. This has a double bond contained between carbons 2 and 3, and has a methyl off of four and an methyl off of six. The longest chain is eight (follow the longest chain of carbons).
4,6-dimethyl-2-octene
This is an alkene, because of the double bond.
D. This has an ethyl group at 1 and a methyl group at 2 (rotate the compound to make it as clean as possible, in this case, the ring is flipped and rotated to make it alphabetical with the smallest numbers possible). The two names are:
1-ethyl-2-methylbenzene
ortho-ethylmethylbenzene
Both are correct, the ortho prefix telling the location of the ethyl and methyl groups. This is an aromatic structure because of its double bonded ring.
E. The longest chain is nine, and has methyls at three, five, and seven, along with a propyl at five. The name is:
3,5,7-trimethyl-5-propylnonane
This is an alkane, due to the single bonds.
Hope this helps!
The mass of a 0.513 mol of Al2O3 is 52.33g.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the molar mass of the substance by its number of moles. That is;
mass of Al2O3 = no. of moles of Al2O3 × molar mass of Al2O3
According to this question, there are 0.513 moles of Al2O3.
Mass of Al2O3 = 0.513 × 102
Mass of Al2O3 = 52.33g
Therefore, the mass of a 0.513 mol of Al2O3 is 52.33g.
Learn more about mass calculations at: brainly.com/question/8101390?referrer=searchResults