Which of these statements is correct?

Chlorofluoro carbons are air-polluting agents. They are produced by –

Katen [24]

Answer:

C. Aerosols

Explanation:

8 0

3 years ago

What is the concentration of a solution in which 60 g of NaCl are dissolved in 1.0 L of water?

Dima020 [189]

What am I answering????

7 0

3 years ago

Which of the following statements is/are correct?

7nadin3 [17]

Answer:

All are correct

Explanation:

1) The angular momentum quantum number, l, are the subshells within a shell (principle quantum number) it talks about the "form" of an orbital, the number itself tells you about the number of angular nodes (a plane without electronic density). It starts at l=0 where you don't see any nodes and it takes the form of an sphere, and we knowing it bu another name an s-orbital. It takes values up to n-1.

l=0 (sphere - s-orbital)

l=1 (p-orbital)

l=2 (d-orbital)

2) The magnetic quatum number, ml relates to the number of orbitals within a subshell then it is related with l, taking values form -l to l incluing 0.

For l=0 (s-orbital) ml=0

For l=1 (p-orbital) ml=1,0,-1

For l=2 (d-orbital) ml=2,1,0,-1,-2

3) In every shell we are restricted by the total number of nodes of any orbital. Then if we want a d-orbital with l=3 we need at least 3 plane nodes only achievable with n=3 at least.

8 0

3 years ago

What is the molarity of a solution if 300.0 ml of it contains 16.8 g of kno3? [formula weight: kno3, 101.11 amu]?

AVprozaik [17]

The molarity is count by dividing the mole of the solute within 1 liter of solvent. In this case, the KNO3 is 16.8g with 101.11 g/mol molar mass. Then we need to find the mol first. The calculation would be: 16.8g / (101.11g/mol)= 0.0166 mol.

Then the molarity would be: 0.0166mol/ 0.3l= 0.0498= 0.0553 M

6 0

3 years ago

Read 2 more answers

Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. I

Paha777 [63]

Answer:

There is 9671 Kj of heat released

Explanation:

Step 1: The balanced equation:

C18H36O2(s) + 26O2(g) --> 18CO2(g)+18H2O(g)

This means for 1 mole of C18H36O2 consumed there is 26 moles of O2 needed to produce 18 moles of CO2 and 18 moles of H2O.

Step 2: Calculate the heat of combustion

ΔH (combustion) = [18*(ΔHf of CO2) + 18*(ΔHf of H2O)] - [1*(ΔHf of C18H36O2) + 26*(ΔHf of O2)]

ΔH (combustion) = [18*(-394 kJ/mol) + 18*(-242 kJ/mol)] - [1*(-948 kJ/mol) + 26*(0 kJ/mol)]

ΔH (combustion) = [(-7092 kJ/mol) + (-4356 kJ/mol)] - (-948 kJ/mol)

= -10500 kJ/mol

ΔH (combustion) = heat released / number of moles of stearic acid

Step 3: Calculate moles of stearic acid

moles of stearic acid = mass / Molar mass of stearic acid

moles of stearic acid = 262g / 284.48 g/mole = 0.921 moles

Step 4: Calculate moles of oxygen

moles of O2 = 914.5 / 32g/mole

moles of O2 = 28.578125 moles

Stearic acid is the limiting reactant: it will completely react

There will react 26*0.921 mole = 23.946 mole of O2

This means there will remain 4.63 moles of O2

Step 5: Calculate heat released

q = (ΔH combustion) * (moles of stearic acid) = (-10500 kJ/mol) * (0.921 moles) = 9671 Kj

There is 9671 Kj of heat released

6 0

3 years ago