It get hotter towards the center

Explain why water is polar. Check all that apply. View Available Hint(s) Water is known as a polar molecule because Check all th

sineoko [7]

Answer:

The correct statements that you must check are:

The oxygen atom has a greater attraction for electrons than the hydrogen atom does (second statement).

The electrons of the covalent bond are not shared equally between the hydrogen and oxygen atoms (fourth statement).

Explanation:

Electronegativity is the relative ability of an atom to pull the electrons in a covalent bond.

Hydrogen has an electronegativity of 2.20 and oxygen has 3.44. That means that oxygen attracts the electrons more strongly than hydrogen does (second statement).

As consequence, the electrons in the covalent bond H - O of water are not shared equally (fourth statement): the electron density will be higher around the O atoms.

Of course, this discards the statement telling that hydrogen atom attracts electrons much more strongly than the oxygen atom, and the statement telling that hydrogen and oxigen have same electronegativity.

Such difference in electron densities creates a dipole moment, so you discard the last statement (that the water dipole moment is equal to zero).

7 0

4 years ago

A sample of aspirin weighing 5.945 g became contaminated with 2.134 g of sodium sulfate. The resulting

ira [324]

Answer:

The correct answer to the following question will be "62.9 %".

Explanation:

The given values are:

The aspirin's initial amount = 5.945 g.

and is polluted containing 2,134 g of sodium sulfate.

After extraction we provided 3,739 g of pure aspirin.

Now,

$Percentage \ of \ recovery \ aspirin =\frac{Aspirin \ amount \ isolated \ after \ extraction}{initial \ amount \ of \ aspirin}\times 100$

On putting the values in the above formula, we get

⇒ $=\frac{3.739}{5.945}\times 100$

⇒ $=62.9 \ percent$

Note: percent = %

7 0

3 years ago

"what is the mole fraction, x, of solute and the molality, m (or b), for an aqueous solution that is 16.0% naoh by mass?"

mafiozo [28]

Answer: Mole Fraction of solute = 0.0790

Molality of solute = 4.761 mol/kg

Explanation: We are given that NaOH is 16% by mass in an aqueous solution which means that in 100gms of solution there is 16gm of NaOH present.

Mass of NaOH in aqueous solution = 16gms

Mass of water in aqueous solutin = 84gms

We need to calculate the mole fraction and molality of the solute and here solute is NaOH because solute is that substance in the solution which is present in low quantity.

To calculate the mole fraction, we will use the formula

$\chi =\frac{\text{moles of solute}}{\text{total moles in a solution}}$

and now to calculate mole fraction, we first need to find out the moles which can be calculated by

$\text{number of moles} =\frac{\text{Given mass}}{\text{molar mass}}$

Molar mass of NaOH = 40g/mol

Molar mass of $H_2O$ = 18g/mol

$\text{Moles of NaOH} =\frac{\text{16g}}{\text{40g/mol}}$

Moles of NaOH = 0.4mol

$\text{Moles of water}=\frac{\text{84g}}{\text{18g/mol}}$

Moles of water = 4.66mol

So, $\text{Mole fraction of NaOH}=\frac{\text{0.4mol}}{\text{0.4mol+4.66mol}}$

Mole fraction of NaOH = 0.0790

Now, to calculate molality, we use the formula

$\text{molality}=\frac{\text{moles of solute}}{\text{mass of solvent(in kg))}}$

mass of solvent (in kg) = $\frac{84g}{1000g/kg}$

Mass of solvent = 0.084kg

and we have already calculated the moles of solute above, by putting the values in the above equation, we find the molality.

$\text{molality of NaOH}= \frac{0.4}{0.084kg}$

Molality of NaOH = 4.761 mol/kg.

3 0

3 years ago

the rate of disappearance of Br- at some moment in time was determined to be 3.5 x 10-4 M/s. What is the rate of appearance of B

ddd [48]

Answer:

1.8 × 10⁻⁴ mol M/s

Explanation:

Step 1: Write the balanced reaction

2 Br⁻ ⇒ Br₂

Step 2: Establish the appropriate molar ratio

The molar ratio of Br⁻ to Br₂ is 2:1.

Step 3: Calculate the rate of appearance of Br₂

The rate of disappearance of Br⁻ at some moment in time was determined to be 3.5 × 10⁻⁴ M/s. The rate of appearance of Br₂ is:

3.5 × 10⁻⁴ mol Br⁻/L.s × (1 mol Br₂/2 mol Br⁻) = 1.8 × 10⁻⁴ mol Br₂/L.s

3 0

3 years ago

How does technology help scientists know more about the atom

Digiron [165]

Scientists unveil new technology to better understand small clusters of atoms. Summary: Physicists have developed new technology to study atomic vibration in small particles, revealing a more accurate picture of the structure of atomic clusters where surface atoms vibrate more intensively than internal atoms.

7 0

3 years ago

It get hotter towards the center￼

It get hotter towards the center