What volume is needed to store 0.050 moles of helium gas at 2 atm and 400k?

A 250-mg sample of carbon from wood underwent 15300 carbon-14 disintegrations in 36 hours. Estimate the time since the death of

goldenfox [79]

Answer:

The correct answer is - 9935 years approximately.

Explanation:

Let z be the age in years to be found:

(15300 disintegrations) x (1.0 g / 0.250 g) / (1.84×10^4 disintegrations)

= 3.3260

half life of carbon = (1/2)^(z/5730 yr)

Solve for z

3.3260 = (1/2)^(z/5730)

Take the log of both sides:

log 3.3260 = (z/5730) log (1/2)

log 3.3260 / log (1/2) = z/5730

z = 5730 log 3.3260 / log (1/2)

= 1.73378816*5730

= 9935 years approximately.

4 0

2 years ago

The combustion of 0.590 g of benzoic acid (ΔHcomb = 3,228 kJ/mol; MW = 122.12 g/mol) in a bomb calorimeter increased the tempera

Alenkinab [10]

Answer:

2.943 °C temperature change from the combustion of the glucose has been taken place.

Explanation:

Heat released on combustion of Benzoic acid; :

Enthaply of combustion of benzoic acid = 3,228 kJ/mol

Mass of benzoic acid = 0.590 g

Moles of benzoic acid = $\frac{0.590 g}{122.12 g/mol}=0.004831 mol$

Energy released by 0.004831 moles of benzoic acid on combustion:

$Q=3,228 kJ/mol \times 0.004831 mol=15.5955 kJ=15,595.5 J$

Heat capacity of the calorimeter = C

Change in temperature of the calorimeter = ΔT = 2.125°C

$Q=C\times \Delta T$

$15,595.5 J=C\times 2.125^oC$

$C=7,339.05 J/^oC$

Heat released on combustion of Glucose: :

Enthaply of combustion of glucose= 2,780 kJ/mol.

Mass of glucose=1.400 g

Moles of glucose = $\frac{1.400 g}{180.16 g/mol}=0.007771 mol$

Energy released by the 0.007771 moles of calorimeter combustion:

$Q'=2,780 kJ/mol \times 0.007771 mol=21.6030 kJ=21,603.01 J$

Heat capacity of the calorimeter = C (calculated above)

Change in temperature of the calorimeter on combustion of glucose = ΔT'

$Q'=C\times \Delta T'$

$21,603.01 J=7,339.05 J/^oC\times \Delta T'$

$\Delta T'=2.943^oC$

2.943 °C temperature change from the combustion of the glucose has been taken place.

8 0

3 years ago

Compared to ultraviolet light, an electromagnetic wave that has a higher frequency will also have ________. (4 points)

Jet001 [13]

Answer: shorter wavelength and equal speed

5 0

3 years ago

The monomer of poly(vinyl chloride) has the formula C2H3Cl. If there are 1,565 repeat units in a single chain of the polymer, wh

monitta

Answer:

$\large \boxed{9.780 \times 10^{4}\text{ u}}$

Explanation:

The molecular mass of a monomer unit is:

C₂H₃Cl = 2×12.01 + 3×1.008 + 35.45 = 24.02 + 3.024 + 35.45 = 62.494 u

For 1565 units,

$\text{Molecular mass} = \text{1565 units} \times \dfrac{\text{62.494 u}}{\text{1 unit }} = \mathbf{9.780 \times 10^{4}}\textbf{ u}\\\\\text{The molecular mass of the chain is $\large \boxed{\mathbf{9.780 \times 10^{4}}\textbf{ u}}$}$

8 0

2 years ago

Which situation would lead to increased competition

I am Lyosha [343]

I would say B because c and d would decrease competition and a would do the same, or just kill the ecosystem.

Hope this helps and don't forget to hit that heart :)

8 0

2 years ago