Can someone please help!! I’m in a test!!

According to Dalton, what happens to atoms during a chemical reaction? Atoms gain or lose energy. Atoms are rearranged. Old atom

Hunter-Best [27]

Answer:

Atoms are rearranged.

Explanation:

7 0

3 years ago

The solubility of oxygen gas in water at 40 ∘c is 1.0 mmol/l of solution. What is this concentration in units of mole fraction?

juin [17]

The formula for mole fraction is:

$mole fraction of solute = \frac{number of moles of solute}{total number of moles of solution}$ -(1)

The solubility of oxygen gas = 1.0 mmol/L (given)

1.0 mmol/L means 1.0 mmol are present in 1 L.

Converting mmol to mol:

$1.00 mmol\times \frac{1 mol}{1000 mmol} = 0.001 mol$

So, moles of oxygen = 0.001 mol

For moles of water:

1 L of water = 1000 mL of water

Since, the density of water is 1.0 g/mL.

$Density = \frac{mass}{volume}$

$Mass = 1.0 g/ml\times 1000 mL = 1000 g$

So, the mass of water is 1000 g.

Molar mass of water = 18 g/mol.

Number of moles of water = $\frac{1000 g}{18 g/mol} = 55.55 mol$

Substituting the values in formula (1):

$mole fraction = \frac{0.001}{55.55+0.001}$

$mole fraction = 1.8\times 10^{-5}$

Hence, the mole fraction is $1.8\times 10^{-5}$ .

7 0

3 years ago

The minimum energy required to break the oxygen-oxygen bond in oxygen is 495 kJ/mol. What is the longest wavelength of radiation

Sergeeva-Olga [200]

Answer:

241 nm, it is UV light range

Explanation:

The minimum energy needed required to break the oxygen-oxygen bond = 495 kJ/mol

Energy needed for 1 molecule of oxygen = 495 × 10³ J / avogadro's constant = 495 × 10³ J / ( 6.02 × 10²³) = 8.223 × 10⁻¹⁹ J

Energy = hv

where h = Planck constant = 6.626 × 10 ⁻³⁴ m²kg/s and v = frequency

c speed of light = vλ

c / λ = v

E = hc / λ

λ = hc / E = (6.626 × 10 ⁻³⁴ m²kg/s × 3.0 × 10 ⁸ m/s) / (8.223 × 10⁻¹⁹ J) = 2.41 × 10⁻⁷m = 241 nm

UV light wavelength is between 400 nm - 10 nm

4 0

3 years ago

I really need help on this it’s a major grade!!

Murrr4er [49]

Juan is taking out a loan for $2,500 with an annual compound interest rate of 7% for 3 years Juan will not make any additional deposits or withdrawals how much interest will he have to pay at the end of the loan period.

3 0

3 years ago

What is the ionic & net ionic equation of and their properties (aq, s, l, g) :

alexdok [17]

Kansas City, Missouri, is often abbreviated as KC (abbreviations often refer to the metro area). It is officially nicknamed the City of Fountains. With over 200 fountains, the city claims to have the second most in the world, just behind Rome.

6 0

3 years ago